I dont know anything about this but does this have something to do with so called events?
For monsters, events are used for some "behavior logic". All of this is handled by a method called "HandleAnimEvent" which is overridden by each monster.
For example, the zombie has 3 events : "Attack slash left", "attack slash right", "attack slash both". Let's say that the "attack slash right" animation is played, once the animation frame call the event, "CZombie::HandleAnimEvent" is called with the parameter "ATTACK_SLASH_RIGHT", and all the attack logic is done (trace the line, check if it hit something, apply damage...)
In other words, you disable the events, the attack logic is never called even if the zombie play the animation ^^