Mentioned here.
And my NFL rulebook says: 8-1-5 "Any forward pass (legal or illegal) becomes incomplete and the ball is dead immediately if the pass strikes the ground or goes out of bounds."
Here was the way it was put on the Gamebook.
3-8-ATL 19 (10:24) (Shotgun) M.Ryan pass deep middle to R.White to ATL 39 for 20 yards [E.Mack]. FUMBLES (J.Phillips) P11
[E.Mack], RECOVERED by TB-S.Piscitelli at ATL 44. S.Piscitelli to ATL 41 for 3 yards. S.Piscitelli pass
incomplete short left to C.June.
PENALTY on TB-E.Mack, Roughing the Passer, 15 yards, enforced at ATL 37. X12
Penalty on TB-S.Piscitelli, Illegal Forward Pass, declined. No fumble for White because roughing the passer penalty happened while the ball was in the air. White credited with a catch for 18 yards as the roughing the passer penalty was enforced from where he caught the ball.
Or "the end of the run," I presume. Declining the illegal forward pass penalty means it's just a straight RTP foul on B, which would be enforced from the end of the run (as it apparently was). The fumble, the IFP and the subsequent "recovery" (I forget by whom - didn't see it and it was hard to tell listening to it on the radio) just muddied the waters for me.
I look forward to seeing Pereira sort this one out on Wednesday.