It really depends on what offers were already had. We don't know, but if speculation is true you've been offered a lot more than a 1st and a B prospect. If that's all you get, well then it's Chevy's fault. If you have him sit because you are only being offered a 1st and a B prospect, again it's Chevy's fault.
In either of these scenarios Chevy overestimated the leverage he held.
As for your other question, I can understand not trading him for just a 1st and B prospect. Maybe it's better to just force him to sit, but you still have to go back and ask yourself was there a better offer made beforehand, and if there was (which there most likely was) it's Chevy's fault.
If it's true that Trouba is limiting the number of teams that he will willingly sign with, then perhaps the quality of previous offers is moot, since Trouba's camp declined them?