Not "perhaps", certainly. BM wouldn't be a NHL GM if he didn't try to trade a mid-cap player before resorting to waivers. As for Montour, I wouldn't guess either way. Cap issues are quite the brick wall for many franchises these days.
You kind of glossed over the key point, which is that Montour isn't someone who would be added to sweeten a deal. And, furthermore, there is zero evidence to suggest that he has been. Saying you wouldn't guess doesn't really address it. The point is that it was a ridiculous statement, because Montour is a highly touted prospect with very good upside. If you're going to say that he was offered, and not just offered, but that it wasn't enough, I'd ask for evidence.
I'd ask for evidence if it were Theodore or Larsson too. If it were a lesser prospect like, say, Roy or Welinski, I might say it has merit. But Anaheim is very high on Montour, and he's given them every reason to believe that their opinion of him is justified. If Anaheim offered him up in a deal for Stoner, it's a good bet a team would take it. Montour's value exceeds that of Stoner, and he has the potential to be a much, much better player. I think any GM would take that deal in a heartbeat, and work out how to get rid of Stoner(if they wanted to) at a later point. You don't pass up an opportunity to acquire a late bloomer like Montour.