Despite being a long-time Bills' fan, I had previously seen numerous replays and I thought it had been proven to me that the call was correct.
I just looked at a few replays again, and based on the stated interpretation of the rule it is again shown to be correct. However, I don't think I agree with the interpretation of the rule. They say it's based on the flight of the ball. Wychek is standing just behind the 25 yard line and turns perpendicular to the end zone before throwing so they say when he released the ball, it was over the line. Where Dyson catches it, it is over the line. From certain angles it appears that the ball does travel slightly backwards but I'm not sure.
Of course, the optics are affected by Dyson reaching back for the ball so when you see Wychek's feet behind the line and Dyson's feet are over the line, it seems like a no-brainer forward lateral. Had Wychek thrown the ball where Dyson was standing, it would've been an easy call.
As far as the rule being based on position of the ball, I guess it's similar to the goal line. A player can be stopped with his feet outside the end zone but if he reaches over the line with the ball, it's a TD. If a player's feet are in the end zone but the ball doesn't cross the goaline, it's not a TD. On this play, where the ball is when it's caught is the decider. I'm just not convinced that where the ball was when Wychek released it is further over the line than where Dyson caught it.
The play lives on infinany. Hope this doesn't bring back nightmares for anybody.