## Facts

- Twelve-year-old Damechie Mitchell, who could not swim, accompanied the Gonzales family and their 14-year-old son, Luis, to Lake Gregory on July 4, 1985.
- Damechie’s mother testified she warned Matilde Gonzales that Damechie could not swim and should not go into the water; Matilde denied receiving that warning.
- Without adult knowledge, Damechie and Luis took a paddleboard onto the lake; Damechie reiterated he could not swim and asked Luis to help if he fell in.
- Luis rocked the paddleboard until it tipped, throwing both boys into the water.
- When Damechie attempted to hold onto Luis, Luis pushed him away; Damechie drowned.
- Damechie’s parents sued Jose and Matilde Gonzales and Luis Gonzales for negligence, alleging inadequate supervision and allowing a dangerous situation.

## Issues

1. Whether juries in California negligence cases should be instructed on cause in fact using a “but-for” proximate cause instruction (BAJI No. 3.75) or the “substantial factor” instruction (BAJI No. 3.76).
2. Whether giving BAJI No. 3.75 and refusing BAJI No. 3.76 was prejudicial error requiring reversal.

## Decision

- The California Supreme Court disapproved BAJI No. 3.75 as a standard causation instruction and directed that it not be given in future cases.
- The Court approved instructing juries on cause in fact using the “substantial factor” test reflected in BAJI No. 3.76.
- The Court held the trial court’s refusal to give BAJI No. 3.76 and its use of BAJI No. 3.75 constituted prejudicial instructional error.
- The judgment for defendants was reversed and the matter remanded for a new trial.

## Legal Principles

- In California negligence cases, causation in fact is properly stated as whether the defendant’s conduct was a “substantial factor” in bringing about the harm.
- A “but-for” formulation that tells jurors the injury would not have occurred “without” the defendant’s act can be misleading where multiple acts may have contributed to the injury.
- Causation instructions should reflect that more than one negligent act may be a legal cause of an injury, consistent with comparative negligence and concurrent causation.
- Use of confusing “proximate cause” terminology and rigid “but-for” phrasing may improperly suggest that if another cause appears more immediate, the defendant’s negligence cannot be a cause.

## Conclusion

The court required use of the substantial-factor test for cause in fact and held that the traditional “but-for” proximate cause instruction was misleading and, in this case, likely caused the jury to reject causation despite finding negligence, warranting a new trial.


Mitchell v. Gonzales, 54 Cal. 3d 1041 (Cal. 1991)