I don't see why management would let him negotiate like that. He had a bad regular season, I think he shouldn't of been in a position to do that.
Lombardi has said publicly on multiple occasions, especially recently that he feels he is to blame for Stoll's numbers, putting Stoll into roles he's not suited for since DL didn't find a player for said roles. Now he's confident with Stoll in his current third line center role. And let's face it, Stoll took a pay cut to stay so probably DL was willing to give him term.