Bruce says nothing. Instead, he tilt his head, studying Stiles intently. Then, to Derek, "His assignment was observation, nothing more. Which he knew." And disobeyed. There is only one circumstance in which he allows those undergoing his training to disobey his orders, and this is one of them. Regardless of whether or not 'Matches' could take care of himself--

(He thinks about Stephanie, just before Black Mask captured her--)

-- Is irrelevant. To Stiles, "Your choice was fundamentally the correct one. In the future, you need to trust that I've considered every possible angle and accounted for it. Understood?" It's praise, however faint, and from someone as demanding as Bruce it's rather remarkable for that reason alone.