Sometimes you can summarize an opinion very succinctly. Using only three or four sentences of the opinion to get the point fairly clearly.
That's the case here. About which you need know very little more than this:
"Labor Code section 4850 provides that when a public safety officer (like each plaintiff here) "is disabled, whether temporarily or permanently, by injury or illness arising out of and in the course of his or her duties, he or she shall become entitled, . . . to a leave of absence while so disabled without loss of salary . . . ." The principle question [see below] in this case is whether Los Angeles County's policies concerning payment for excess accumulated vacation hours violate section 4850. . . . [Taken together, these policies mean] that, for example, a deputy who has accumulated excess vacation hours, but who has never been injured on duty, might collect more in retirement benefits than a deputy who has been injured on duty, even if the two have the same employment history in terms of rank, years of experience, and so on. It also means that a deputy who retires after taking leave due to a non-job-related injury, perhaps a ski accident, might collect more than a deputy who retires after having suffered an injury in the course of his or her duties, even if the deputies are in other respects identical. Plaintiffs' theory is that this different treatment violates section 4850. The trial court agreed, as do we."
You can read the whole thing. But as a matter of both doctrine and equity, it seems right.
P.S. - I'd just probably quibble with the "principle question" part. Yeah, it's a question about a principle. But I think that Justice Armstrong actually means that it's the principal question. A tiny -- but extant -- difference.