Look, when it was your 'inheritance' on the line, you could call bullshit on a deer who had the command of two remarkably heavily armed and armoured stags with bladed antlers and magical scythes in the room next door. Sure, he was pretty confident she was bluffing. In fact, he was almost certain of it. Buuuut given what he knew of deer, and the rather lethal look she had in her eyes at that point in time... Well, better to lean on the safe side of things. Taking a joke that far wasn't worth it.