The hesitation worries him. Like I said before, while he has trouble with subtle motivations, Jack isn't stupid. Sinclair's been perfectly eloquent up until Jack asked about the prison.

He listens patiently, no longer flat against the wall but not turning his hand off either.

Then Sinclair mentions ol' Andy Ryan, ol' buddy ol' pal and his neat little political talking points, and Jack's face just sours.

"...You're Ryan's man."