Joe McDonnell makes the picks. Nill, as most GM's, doesn't scout that much since they're running the team. When you hear a GM is scouting a prospect, it's either at a big tournament that the rest of the hockey world is at or it's a team with a high pick and the GM is scouting to take someone Top 5.
Nill's probably not seen a guy play before he's drafted since his Detroit days with the exception of high picks or guys in international tournaments. His fault lies in not making changes with the scouting staff or philosophy ... which is a major fault potentially. As far as individual players though, with the exception of Kamloops players, that's on individual scouts and McDonnell. It's dumb but it's also common for an NHL owner who has a CHL team to have guys taken from that team. It's nepotism. Carolina did it with the last owner.
When you hear Nill's been scouting someone, it's typically an undrafted free agent they're trying to entice ... like he did with Bayreuther. That's less about Nill's talent evaluation and more about proving to the kid how serious the team is in adding him. You often hear that the team GM was a big part of the scouting effort of undrafted free agents.