Proving Causation in a Texas Legal Malpractice Case: Why It’s Often the Hardest Element to Win
Legal Malpractice
The element that quietly kills more cases than any other is not breach, ethics, or damages—it is causation.
Clients arrive convinced their former lawyer “ruined everything.” Defense counsel often concede, at least for argument’s sake, that the work fell below professional standards. Yet when the case reaches a Texas courtroom, judges repeatedly grant summary judgment because the plaintiff cannot prove that the attorney’s mistake actually changed the legal result. Under Texas law, a plaintiff must show that, but for malpractice, the outcome of the underlying matter would likely have been better.
Causation is not about how bad the representation looked; it is about constructing, with evidence and admissible opinion testimony, the result that should have been achieved. That is why many Texas legal malpractice lawsuits are decided at summary judgment: the court finds that the client has not tied the lawyer’s conduct to a concrete, legally recognizable injury. The central question is always, Can we prove, with admissible evidence, how the case should have come out if the lawyer had done the job correctly?
Causation in Texas Legal Malpractice
Texas courts frame proximate cause in legal malpractice as having two components:
- Cause in fact – the client must show that, but for the lawyer’s conduct, the outcome would have been more favorable; and
- Foreseeability – the type of harm must have been a reasonably predictable result of that conduct.
In Rogers v. Zanetti, the Texas Supreme Court reaffirmed that a client must do more than point to “bad lawyering.” The court demanded concrete reasoning that links what the lawyer did (or failed to do) to a specific lost claim, adverse judgment, or increased payout. In Alexander v. Turtur & Associates, the Court stressed that breach of the standard of care and causation are “separate inquiries,” and that negligence—even if assumed—does not automatically carry causation with it.
Because of these standards, the best Texas legal malpractice attorney can explain exactly how each alleged error changed the legal or financial outcome, not just why the work fell below professional norms.
The “Case Within a Case” Requirement
When the malpractice arises from prior litigation, Texas treats causation as a “suit within a suit.” Texas legal malpractice lawyers must prove that, if the original case had been handled correctly, the client probably would have obtained a better judgment or settlement.
That usually requires:
- reconstructing the underlying liability and damages as if a competent trial team had handled discovery, motion practice, and trial strategy;
- showing how key rulings—summary judgment, jury charge, evidentiary exclusions—would likely have changed; and
- presenting opinion testimony from qualified attorneys about how a reasonably careful lawyer would have tried the case and what result would likely have followed.
In practice, Texas courts expect plaintiffs to present a full “case within a case”: complete court records from the underlying matter, key communications showing how decisions were made, and opinion testimony tying specific attorney errors to a different probable outcome. This is where a Houston legal malpractice attorney either succeeds in demonstrating causation with concrete evidence or sees the claim end at summary judgment because that evidentiary link is missing.
Judicial Error and Other “Superseding Causes”
Causation becomes even more demanding when another actor (especially a judge) stands between the lawyer’s conduct and the client’s loss. In Stanfield v. Neubaum, the Texas Supreme Court adopted the “judicial error rule,” holding that a trial court’s independent legal error can operate as a superseding cause that breaks the causal chain, cutting off liability for the attorneys.
For plaintiffs, this means that a Texas legal malpractice claim can fail even when the lawyer clearly missed arguments or evidence, if the Supreme Court concludes that the real engine of the loss was the judge’s ruling, not counsel’s conduct. Legal causation in these scenarios turns on careful parsing of:
- what the trial court did wrong;
- what the lawyers reasonably could have done to prevent or cure that error; and
- whether the judicial mistake was so independent that it severs causation as a matter of law.
Lost Settlement and Transactional Causation
Not every claim turns on what a jury would have done. Some of the most technical causation fights in legal malpractice Texas cases involve lost settlement opportunities and transactional work.
Recent Texas appellate authority, including decisions discussed in commentary on Chamblee Ryan, P.C. v. JBS Carriers, Inc., underscores that, when the alleged wrongdoing is failure to convey or properly advise on a settlement demand, opinion testimony is usually required on both causation and damages. The client must show, with more than hindsight speculation, that:
- the settlement would likely have been accepted;
- the terms were materially better than what ultimately occurred; and
- a reasonable attorney, acting carefully, would have recommended that resolution.
In transactional malpractice such as faulty contracts, missed liens, and botched corporate deals, Texas legal malpractice lawyers must often prove a “difference in position” theory: the economic gap between the structure the client actually received and the structure a competent lawyer would have secured. That often turns on market data, deal documents, and testimony from qualified industry and legal professionals, making causation a detailed financial exercise rather than a simple negligence story.
Call the Best in Texas Legal Malpractice Causation Claims
When causation is the element at issue in a legal malpractice Texas case, The Kassab Law Firm brings focused trial and appellate strategies that reconstruct the case within a case, marshal admissible opinion testimony, and address judicial error and lost-settlement theories in line with Texas standards. If you believe your prior lawyer’s mistakes changed the true outcome of your lawsuit or transaction, let Texas legal malpractice lawyers at The Kassab Law Firm review your file, explain your options, and pursue the recovery you may be owed—call us today.