[Koopla]

what it is, is the delay server side and client side. The bot casts cure at 75% the server waits for the animation of said cast to finish(not the cast time) to apply the heal so the bot sees after casting cure that the target is still below the 75% so it starts to cast it again, but then server updates and first heal lands. This is what is causing double casting. You can see it with things like heals and other things like defensive CDs there is talk about this on the SE forums whre you use hallow ground it goes on CD and you still die because the server waits for the animation AFTER the cast of the skill to apply the effect.

I was thinking it might be because of delay/lag... I'm not even sure if it's possible to fix by writing bot code, I mean a live player can see beforehand how many heals it will take and plan accordingly. I guess this is one thing that a bot won't be able to do better than a live player.