Jack shakes his head and it's a confirmation, no, it's not just a dream.

"Yes it was," Sinclair assures him, "we're gonna get you outta here as just as soon as we can, I swear it. You're not gonna be stuck here as long as I have anything to say about it."

And just like that, the situation becomes something he can handle. He has an objective: laying the groundwork for a future conversation, if he can't get it out of him right now.