I wouldn’t be too worried about him not being out by 10 p.m. Whenever I have had overwintered hogs back, I have sat and waited for them to make an appearance until after 12, and they still haven’t been out. By the next morning they have been gone. They haven’t returned to the boxes they were released in (cardboard boxes) even though they were left there for about a week. They did come back for food, though. So they won’t necessarily return to your hog boxes. I would expect him to have been out later, during the night. Do you know whether he has?