In a time critical situation, a backward pass thrown out of bounds would be a foul. Since the backward pass did not go out of bounds, the pass is legal (although exceptionally stupid).
The coach being beyond the coaching line is a UNS foul.
The coach interfering with the ball is not a ‘specific’ foul, but certainly falls under 9-2-3-c, Unfair Acts.
The ball touching something other than a player or an official in the field of play makes the ball dead. By rule, inadvertent whistle rules apply.
First, Team A can take the ball where possession was lost, or they can (ostensibly) repeat the down at the previous spot. They ain’t gonna take the ball where possession was lost. Previous spot.
Then we deal with the foul(s).
Since the coach’s actions were, essentially, a single continuous action, conventional direction is to consider this only one foul. 15 yards from succeeding spot, first down. This is a blatant foul, and I would hope every coordinator would support calling this a flagrant UNS, with offender DQ’d.
By the way, because of the IW rule being enforced, the game clock is started on the RFP.
Robert