Not at all. I am saying that a play begins with the snap and ends with the referees whistle. Possession and location of the ball are determined then. If the team that snapped the ball has possession at the whistle, then down and distance to line to gain are based on the situation at the snap. (next down, line to gain if the dead ball spot is not beyond the line to gain). If the defense has possession at the whistle, then that team has the ball with first down etc.
In your scenario, under my theoretical rule, the defense would have possession at the spot the play was whistled dead.
In a more analogous situation, if a defender intercepts a pass, makes one or more football moves, then is tackled and fumbles and the team originally on offense recovers, the dead ball spot with respect to the line to gain at the start of the play would control whether or not it was a first down. If the spot was not past the line to gain, then it would be the next down.
Example: Team A has the ball 2nd down, 7 yards to go at their own 30. Defender from team B intercepts at the 50, runs, is tackled and fumbles. Team A recovers said fumble at their 35 yard line. Under my hypothetical rule, team A would the ball with third down and two yards to go.
Alternatively if the fumble recovery and ensuing dead ball spot was the 40 yard line, team A would have first down there.
Bottom line, I am not in favor of declaring "change of possession has occurred" until the whistle declaring end of play has sounded.
