Yeah, Foreman always comes across as unwavering in his stance, most of the time, whether it be against the wishes of others or not. And i think the worry we saw on House's face outside the office in that episode was a reflection of that. If it was someone along the lines of Cuddy or Wilson then he may have been more reassured that he definitively would NOT have gone back to jail.

Foreman's issue is that he's giving mixed signals. One week his taking House to boxing matches, the next he's threatening jail time, and I totally agree, he is eroding his position by trying to be a pal and trying to be this staunch, immovable object of a boss all at the same time.