This is going to be tricky to explain to A's coach. There will likely be a flag on the ground for DPI, which will be waved off after it's learned that the QB was past the LOS.
Take your time, let him vent a little, and choose your words carefully.
A MAINER : "AYUH, 'spect your thrower had wandered over that there line where the down box is before he threw 'er. We caught him doing that so there can't be no pass interference as your thrower didn't do 'er right. Ayuh, them other guys got ta' ball an took 'er in, 'spect we'll put their score up. Sorry chummy."
A 'bama : " Y'all had a quarterback over the....."
RULE BOOK : 2-3-5b gives rule support for letting play stand. The pass has to be legal for pass interference to be considered.
TTTA (things to think about) ON THIS:
(1) If fumble by B had gone OOB in field of play, B's ball there;
(2) if fumble by B had gone OOB thru EZ = TB = take the IFP penalty;
(3) If foul had occurred on a 4th down play, taking the penalty may give better
field position if B didn't have long return;
(4) R & U can beanbag QB's feet to mark spot of pass;
(5) Suggest going to spot of IFP first, giving preliminary S#35 followed by going
to spot of DPI flag, point to it and S #13;
(6) Follow that with your visit with A's coach to explain. By giving the preliminary
signals before the discussion will indicate that this won't be a debate but
merely an explanation .