City of Petaluma v. Workers' Comp. Appeals Bd. of State

*1179 INTRODUCTION

In 2004, the Legislature made comprehensive changes to the workers' compensation law, one of which altered apportionment of permanent disability such that an employer is now liable only for the percentage of disability directly caused by the employment-related injury. In the instant *99 case, the Qualified Medical Examiner (QME) concluded 85 percent of the claimant's disability was due to a previously asymptomatic, underlying condition. The Administrative Law Judge (ALJ), however, determined no portion of the disability should be apportioned to that condition. The Workers' Compensation Appeals Board (the Board) affirmed, stating the QME had "confused causation of injury with causation of disability." We granted the City's petition for a writ of review and now annul the decision and order an apportioned award.

BACKGROUND

The parties stipulated that the claimant, Aaron Lindh, was employed as a law enforcement officer when he "sustained injury arising out of and in the course of employment to his left eye." More specifically, Lindh took three to six blows to the left side of his head while engaged in a canine training course. Afterwards, he "suffered severe…