Back in the world of darkness days my group witnessed what was most likely a heal bot on a script. It would unsheath its weapon and slowly walk towards the F2 player, sheath the weapon then cast medica and do it all over again every few seconds. Another time we found one that if you typed in /say Cure it would cast CureII and then Medica II regardless of healing need and always targeted the same person.

Most are probably just distracted/drunk/sleepy/bad or whatever but I do believe some are legit bots.