I'm sure others have said it (I didn't read all 17 pages of this thread), but there's a lot of sloppy talk here and elsewhere online conflating when DET scored and when Philly was eliminated. DET scoring did not eliminate Philly, and thus was not particularly relevant to Torts in the moment. The only relevant event is DET securing the point. While this may seem like a distinction without a difference given how late the DET goal came, when we're talking about judging the Flyers/Torts' conduct based on the passage of literally seconds here, the distinction matters. The DET goal could have been reviewed. And then there was some fractional chance MTL scores in the final 3.3 seconds. While there was still time on the clock in DET, no sane human charged with updating Torts about the DET game is going to come barreling down the tunnel to interrupt Tort's coaching a life-or-death game 82 in order to convey the fact that DET seemed LIKELY to have secured a point, because that has zero impact on Torts' strategy. Torts is still going to be playing to his outs by trying to win in regulation until there are no outs left. So you don't update Torts until everything is settled in Detroit. That's just basic common sense.
So when was everything actually settled in Detroit? Again, there's a lot of conflation between when DET scored and when regulation ended. But there was some time lapse between those 2 events. For one thing, the clock had to be reviewed and reset from 0.7 to 3.3 seconds after DET goal. Then there was the normal delay of the teams changing, and lining up for the post-goal faceoff. Then the puck was dropped and the final 3.3 seconds ticked off. Only then is there something to report to Torts. That's the moment when the Philly video guy (or whomever was tasked with that unfortunate job) would have gone to the bench to attempt to convey the news to Torts. But that video guy is not going to literally interrupt Torts in the midst of live play or else he's liable to get slugged. So the video guy is going to wait for the next whistle to inform Torts of DET going to overtime. And I'm almost certain the next whistle after the end of DET regulation was the whistle acknowledging that Washington had scored the empty-netter.
And that's also exactly what Torts said happened. He explicitly said in the post-game presser that he was told about the DET result right after Washington scored. That lines up.