what happens is the Bulette opening move knocks everything prone by scrypt and that means the 2nd pet gets locked out of the battle if its in the area
[see image]
because as far as the game knows this 2nd monster is actually Gut's pet i.e, a special case of pet of a pet and no one at Larian told the game how to handle that senario


if this happens and Gut dies during the fight then this locks the pet and all you can do is kill it or ignore it
if gut lives [and isn't somehow made hostle] then the pet will unlock once the battle is finished