Yeah I was in the Battle Maison and the computer used Roar and it went first. I don't know how that's possible. I tried to use Trick Room just so you know. Here's the Vs. Recorder code:
That's because Roar's priority is -6, while Trick Room's priority is -7.
Roar is therefore in a faster bracket than Trick Room, and will go first. Moves will go in the following order.