Another bug with him happens especially with types of modes like Ninja Exam or SA where there are consecutive battles. If Kakuzu revives after the last unit of the enemy team was defeated, he won't revive teammates and instead continues on to the next battle.

One example on ninja exam 85 (team of 4 vs. a lone orochimaru and then Manda): let's say 3/4's of my team (including kakuzu) got wiped out, but my 4th shinobi defeats orochimaru. Kakuzu then revives himself, but instead of reviving the rest of his defeated lineup the battle continues on to Manda, leaving my team with only two members alive to fight Mr. Manda