The rise after workouts doesn't scare me.
Guys like Lillard who play in small conferences have that built-in to their draft stock their entire careers, IMO. I think the projections always peg them a few spots lower than where they should go because of that built-in fear of "of course he's killing people...look who he's playing against"
The combine and workouts are the first time they're consistently pegged against big-time talent. If they continue to perform well against this quality competition (albeit, typically in vastly different settings than 5-on-5 basketball) it only makes sense that they would rise up draft boards because the fear that they can only dominate sub-par competition is mitigated.
Having said that, I also view Lillard as an unknown. I've only seen him play in very, very small snippets. I'm sure he can play, but there's a difference between being a good player and being our Franchise PG. He better be the latter if we're going to unload Millsap for him.