Ohh, hey what about accidental magic use? I have no idea how you set up magic to work, but I imagine Jeremy doesn't have the greatest control over his magic due to lack of practice since he can't use it ever, unless he'll be found otherwise. Throw in a emotionally high moment and that could be a combination for a random burst of magic, as for that "emotional high"... well I got ideas, heh, and you can guess what that could be; you know Jeremy gets to be alone with Rena in her room and all that.