Luke takes that as a sign that perhaps it's better to not risk it. He lingers a few minutes longer, so as not to look like he's scurrying off and arousing suspicion. No worse way to wind up in trouble than to get something, then get yourself caught by being too hasty. He makes certain to keep looking busy, and move at a slow, ambling pace, buried in his notes.

If there was anything to see as he makes his way out, then he'd be on the lookout. He'll try with the Force too, unreliable as it is, the sixth sense is still better than just five.

If not, then out he goes, palming the notes he's taken.