I was in one of those odd runs recently as well. I was on my cleric. Our chew toy was a wf so the two wizzys were on watch and I was running around with the kill team. I heard the wizzy kind of panic as the puppy lost interest in said chew toy and beelined for the wizzy. I immediately turned down a hall toward them dropped a few heals on him while the WF fighter regained aggro and we were all well again. It was so strange though as we had all the right setup going and there was no reason for the puppy to decide to taste the wizzy. Thankfully he had enough hp to survive while we fixed the little problem and I got to him to heal.