It's not exactly a matter of smart, since he had no reason to suspect weirdness (besides the door); Fox operates under the assumption that he lives in a universe that isn't so cruel as to have doors to nowhere or sudden pits of spikes or something. Of course... Fox is also under the assumption that a simple bathroom isn't somehow a portal into a blackened abyss in which you can lose small children and pets, and he's mistaken on that one.
Ehhh, while I'm at it...How's this going for you guys? I'm having one of those stretches of time where my general ability to judge my own work completely bottoms out and I become a bit paranoid, so I thought I'd just check in.