Ok, if you still believe DS was willing to give up a 1st and a prospect for a guy he knew didn't want to play for his team let's illustrate how this all likely went down. Because I'm willing to bet when it came out that staal didn't want to go there that DS was still giving the same offer.

I'm sure DS said 'hey Paul, we're interested in Eric and willing to give you a first and a prospect.'

PF 'ok, that sounds reasonable let me talk to Eric and his agent' (now I completely understand that his feelings don't matter, according to his contract. If he was 25 we would've just shipped him, no questions asked. But when a guy is 34 and at the end of a contract and you tell him he's going somewhere he doesn't want to go, he could very easily just retire at that point. Older guys have leverage to not be traded because they can retire and the buying team gets screwed.)

PF 'hey Eric and agent, Boston is interested in you and we have talked about a trade'

ES 'I really don't want to go there. I want to stay in MN with my family. How about I sign a real team friendly deal for you instead of you shipping me off to Boston'

PF 'hey DS, he really doesn't want to go there'

DS 'ok, well if he doesn't want to then I guess we'll move on'

Very basic, cheesy illustration.

I fully understand that the wild could trade him freely, according to his contract. But his leverage of retirement, or frankly, lack of effort, make it so it's a little more complicated than PF and DS being able to do whatever they want.