Yeah, big if, but it certainly does seem like something like that could have happened. Some even had him dropping to 9. Here's what I remember from the mock drafts-
Phoenix - set on either Bender or Chriss, no chance at Brown
Minnesota - really, really wanted Dunn, and I think Hield would have been the pick if Dunn was gone
New Orleans - whatever guard was left
Denver - wanted Bender, ended up taking Murray after he fell a bit
Sacramento - really wanted Hield, ended up with Chriss for the trade
So, yeah, I think there would have been a good chance that he fell that far, but they were understandably not willing to take that risk. At the very least, they could've worked out a deal with Minny and picked up extra assets while still getting their guy. There's absolutely no excuse for not doing that. Minny wanted Dunn BAD, and we could pressured them into giving up some assets to get him. Even without the trade itself, I think it was a failure on our part not to move up with Sacramento.