It mostly happened with the bomb attack and the acid pools. If the bomb was incoming and the bot was trying to eat or drink a potion, it would freeze and then continue doing that - not having enough time to click away from the bomb. If it became venom'd or low hp and it was on an acid pool, it would try to eat/pot instead of moving first.
It would also only eat once per click while walking during that acid pool phase and just couldn't keep up with the dps. Typically when i kill vorkie myself, I would stack a potion sip and food eat in a tick to prevent this. Might help if it could combo eat karambwan/monkfish as well.
I had the BGS selected with a BGS/Void melee helm / Fire cape in the inventory but it always used the blowpipe spec instead. (set to addy darts).