Iain Glen was a very busy guest. When I got my VT for his autograph at around 10:30 (right after my photo with him) I got #360! My number was called at around 1pm, and there were still a lot of people there waiting for their numbers to be called. I didn't leave level 3 until 2:30pm for my next photo, and there was still a long queue for him. And then, he had a second, long photo session in the afternoon. If you got there after his second photo session, maybe he wasn't busy then but I'm sure he was tired. Had he posed with every fan that day, he couldn't have signed all those autographs. Anyway, no posed photos doesn't mean no photos at all. A friend who was there took a picture of him signing my autograph. I took photos of the moment he was signing others'. They had no problems with those photos. The only thing is that the guest (Iain in my case) isn't posing.
I agree though that they had a big problem with clashes, and that there were moments when I thought it really was oversold. But I have not a single complain from the guests.