Killed?? You mean EATEN.
PETA types, the ones who tend toward those kind of conservation careers, aren't real big on personal grooming. Too "corporate" for their taste.
Perhaps the lion, after turning the keeper into food, was fussy. You know, sort of like a 4 year old. One taste, the lion version of "EEUW!" and the lion strolled away...
Sharks don't find people very tasty, either. One bite, thinking it's a different flavor of seal, and they ignore it...