How the hell is it not a routine to check both candidates if you have a testing tool right there? I have seen dumb plot convivences, but this one is especially bad. "Hey we just summoned two beings, one of who is essential for our utter survival. This has never happened before, so we don't have a procedure in place. One of the two summoned claimed to be the kind merciful saintess that will ensure our protection, and she has the same magical aptitude as a saintess, then she immediately threatens to not protect us if we even show the basic dignity and kindness to the other summon. This is fine" Like when it turns out in almost every case that their initial assumption was wrong, they should at least lose their jobs if not their titles of nobility