They were about to re-sign him..as GM...but...
POHO & GM in TOR (which wasn't happening) > POHO & GM in PIT > GM in TOR
I think this is a perceptive point and important not to forget when revisiting the transition last summer between GMs and therefore judging (or pre-judging as has been clearly the case among the small but increasingly frenzied handful of dedicated Dubas supporters) Treliving's hiring and first year on the job.
Speculation about Dubas' move to Pittsburgh was common in the media (and in here) well before the end of the season. When it happened, exactly nobody was surprised and a number of well-known journalists and pundits have stated their belief that Dubas engineered the move by forcing Shanahan's hand. I don't see any reason to not believe this account of what happened and, for me, all the pieces fit that sequence of events. Obviously we can't know for sure about what happened behind closed doors, but there is one thing we CAN know for sure and it is this: If WE heard about Dubas-to-Pittsburgh weeks before it happened, then certainly Shanahan knew about the speculation and would have questioned if there was any truth to it. He would have known a lot more than any of us here on this message board (needless to say, surely!) and more than even the most well-connected pundits. This knowledge -- that perhaps Dubas might want to move or that he wanted more money/term/power -- would have factored into his offer of a renewed contract for Dubas -- as GM only, as pointed out above -- and what that offer meant in terms of salary, term and the scope of the GM's powers. Shanahan is on the record as saying Dubas surprised him in his public statements at that notorious presser; he said he was also not expecting Dubas and his agent to come back a few days later with a different proposal (asking for more of something, obviously) and that this was part of the reason he fired him. Obviously, if you think Shanahan is lying, that's up to you.
I also think the silence on the matter from Dubas afterwards and to this date is telling; there has been no rebuttal against Shanahan's account of things, beyond some rather mild puff pieces by loyal journos in Toronto about how much Dubas would be missed by some unnamed MLSE employees. We're left, as far as I can tell, with just a few anonymous message board minions calling Shanahan 'rash' and 'emotional' without any supporting sources to back them up. I've heard some pundits say they think Shanahan acted to preserve his own position as President, which I can understand. But I don't think that behaviour even qualifies as ruthless, much less hysterical or hasty as some would have us believe.
As for Shanahan's relatively quick hiring of Treliving, I suspect he probably had him lined up as a possibility well before he fired Dubas. It would be irresponsible of Shanahan not to always have an eye on possible replacements. I'm hoping Treliving gets a decent return on a Marner trade at some point soon but that won't be the only factor in my judgement of his ongoing worth as our GM. I'm pleased with some of his moves and like his hiring of Berube as being the next step in a culture shift.
What I know for sure is that we only know a fraction of what happens behind closed doors at MLSE. I don't actually hold out that much hope for ever getting to the truth of the matter of Dubas' firing, to be honest, which is probably how it should be. Yes, these people are all making millions and they owe us some transparency as the fans who allow them to have such high-paying jobs, but they still have a right to some privacy.