If you follow California civil litigation at all, you know that tentative rulings from superior courts are more than procedural housekeeping. They are a window into how judges are actually applying the law right now, in real cases, with real injured people on one side and well-funded insurance defense teams on the other.
On March 25, 2026, Judge L.M. Hayashi of the Sonoma County Superior Court issued a set of tentative rulings covering multiple civil matters, including personal injury disputes. These rulings touch on issues that appear in nearly every serious injury case in Northern California: expert witness challenges, summary judgment motions on negligence, and causation disputes. Because California operates under a uniform civil procedure framework governed by the Code of Civil Procedure, what happens in Sonoma courtrooms carries weight well beyond county lines.
We reviewed these rulings carefully. Here is what injured Californians should take away from them.
Expert Testimony Is a Battleground, and You Need to Be Ready for It
One of the recurring themes in the March 25 tentative rulings involves challenges to expert testimony. Under California Evidence Code sections 720 and 801, a party can move to exclude an opposing expert on grounds that the witness lacks sufficient qualifications or that the opinion is not based on reliable methodology. Insurance defense attorneys file these motions routinely, and when they succeed, a plaintiff’s case can collapse before it ever reaches a jury.
The lesson here is not subtle. If your claim depends on medical causation, which most serious injury claims do, your expert needs to be bulletproof. That means a treating physician or retained specialist who can explain, in precise clinical terms, how the accident caused your specific injuries and why your treatment was medically necessary.
John Reardon spent 20 years as a chiropractor before becoming a personal injury attorney. He has sat on both sides of this issue, as a treating provider whose records were scrutinized in litigation and now as an attorney who builds cases around medical evidence. When we evaluate a client’s claim, we look at the medical documentation the same way a defense expert would, because we know exactly what they are going to attack. Vague chart notes, gaps in treatment, and opinions that outrun the underlying data are all vulnerabilities that defense counsel will exploit at a motion hearing just like the ones Judge Hayashi addressed this month.
Summary Judgment on Negligence Requires More Than a Police Report
Another pattern visible in the Sonoma rulings involves motions for summary judgment on the negligence element of personal injury claims. Under Code of Civil Procedure section 437c, a defendant can move for summary judgment by arguing that the plaintiff cannot establish a triable issue of material fact on one or more elements of the claim. Negligence cases require proof of duty, breach, causation, and damages. Defense teams frequently target causation and breach as the weakest links.
What the Sonoma rulings reinforce is that plaintiffs who rely solely on a police report and their own testimony are vulnerable. A police report establishes that an accident occurred. It does not, by itself, prove that the defendant’s conduct fell below the standard of care, and it rarely addresses the medical connection between the crash and the claimed injuries with any specificity.
To survive a summary judgment motion in 2026, you need layered evidence. That includes witness statements gathered early, photographs and video preserved before they disappear, accident reconstruction analysis where the facts warrant it, and medical records that draw a clear line from the collision to the diagnosis. We start building that record from the first day a client comes to us, because waiting until a motion is filed is waiting too long.
Causation Arguments Are Getting More Sophisticated on the Defense Side
California courts have long required plaintiffs to prove causation under the substantial factor test articulated in CACI 430. But the defense bar has become increasingly sophisticated in how it attacks causation, particularly in soft tissue and spinal injury cases. The Sonoma rulings from March 2026 reflect this trend, with defense motions raising arguments about pre-existing conditions, alternative causation theories, and the adequacy of the plaintiff’s medical foundation.
This is an area where John Reardon’s clinical background gives our clients a concrete advantage. Spinal injuries, disc herniations, and soft tissue damage do not always show up on imaging immediately after an accident. A defense expert who points to a clean MRI taken two days post-collision and argues there is no injury is making a misleading argument, and we know how to counter it. We understand how these injuries develop, how they present clinically over time, and what the peer-reviewed literature says about delayed symptom onset. That knowledge shapes how we work with treating physicians to document your condition from the beginning.
If you have a pre-existing condition, that does not eliminate your right to compensation. Under the eggshell plaintiff doctrine, a defendant takes the plaintiff as they find them. If the accident aggravated a prior back problem, the defendant is liable for that aggravation. But you need medical documentation that distinguishes your baseline condition from the new injury, and that documentation has to be created contemporaneously, not reconstructed months later.
Procedural Deadlines Are Unforgiving, and the Rulings Confirm It
Several of the Sonoma tentative rulings address procedural issues, including untimely discovery responses, late-filed motions, and disputes over whether parties complied with meet-and-confer requirements under Code of Civil Procedure section 2016.040. These are not glamorous issues, but they have real consequences for injured plaintiffs.
California’s statute of limitations for personal injury claims is two years from the date of injury under Code of Civil Procedure section 335.1. Claims against government entities require a government tort claim within six months under Government Code section 911.2. Discovery deadlines, expert designation cutoffs, and motion filing windows are all strictly enforced. Judges in Sonoma County, consistent with Northern California practice generally, are not inclined to grant relief for missed deadlines absent compelling circumstances.
The practical takeaway is straightforward. Delay hurts your case in ways that go beyond the statute of limitations. Evidence degrades. Witnesses become harder to locate. Medical records get harder to obtain. The sooner you retain counsel and begin the formal process of preserving and developing your claim, the better positioned you will be when the defense starts filing motions.
What These Rulings Mean for Your Claim Strategy
Tentative rulings are public records. They are accessible through the Sonoma County Superior Court’s website, and they are citable in subsequent proceedings as persuasive authority on how a particular judge approaches recurring legal questions. Experienced plaintiffs’ attorneys review them regularly because they reveal judicial temperament, the kinds of arguments that resonate, and the evidentiary standards being applied in real time.
For injured Californians, the March 2026 Sonoma rulings send a consistent message. Courts are applying rigorous scrutiny to expert qualifications, causation foundations, and procedural compliance. Insurance defense teams know this, and they structure their motion practice accordingly. A claim that might have survived a more permissive evidentiary environment will not survive if the medical documentation is thin, the expert opinions are conclusory, or the procedural record has gaps.
Building a claim that holds up under that scrutiny requires attention to detail from the very beginning, not after a motion to exclude your expert has already been filed. It requires treating physicians who understand how to document injuries in a way that supports litigation, retained experts who can withstand cross-examination, and attorneys who understand both the medicine and the law well enough to anticipate what the defense is going to do before they do it.
Protecting Your Claim in Light of Current Judicial Trends
If you were injured in a car accident, a premises liability incident, or any other situation caused by someone else’s negligence, the rulings coming out of Sonoma County this month are a useful reminder of what you are up against. The defense bar is well-organized, well-funded, and paying close attention to the same judicial signals we are.
We are a California personal injury firm led by an attorney who practiced clinical medicine for two decades before practicing law. We understand injuries at a level most law firms do not, and we use that understanding to build cases that are prepared for the motions that will inevitably come. If you have questions about your claim, about how recent court rulings might affect your case, or about what steps you should be taking right now to protect your rights, we are glad to talk through it with you. The consultation is free, and you pay nothing unless we recover for you.