Marner declined to waive his NMC. Toronto had told him they still hoped to re-sign him.Marner declined to move to Carolina?
Also, contrary to conventional thinking among fans, I don't think Dundon was about to give GMET the runway to flip Rantanen for another UFA without an extension in hand. I suspect that this was a double sign-and-trade.
If Marner is sold on going UFA (remember he's currently refusing to negotiate with TML either), this was a non-starter.