And here's a different bug that I've just noticed on the FMG path: using the furries' various inherent special skills (so Tail Whip,Milky Way, Shark Bite, and probably Alpha Roar, although I haven't tested that yet as I'm doing a new playthrough) DOESN'T decrement the durations of the boosts granted by the Muscle Crush skill - only normal attacks do. Don't know if it is just the problem with muscle crush, or all "path skills" as I like to call them, or even all boosts as a whole, as I've noticed it by accident by mousing over the boost icon on the character's status bar.
EDIT: Just tested it with boosts applied by fish - this bug happens with ALL boosts - their duration is decremented only by normal attacks.
2ND EDIT: Actually I was only half-right: using items does in fact decrement the duration timers - so perhaps the issue is only with skills.