I'm a new football official so be easy on me
I am going to re-hash the OP with arbitrary yardlines to keep everything straight in my mind.
A’s, 2 and 10 from B’s 20. Team A snaps the ball with 6 men on the line. During the run, A1 fumbles. B1 recovers the ball and starts running. During B1's run, B2 commits an illegal block in the back (spot foul at A’s 35). Near A’s goal line, B1 fumbles the ball, which bounces into and then out of the back of A’s end zone.
1.) B’s was the last to possess the ball before it when into A’s goal and subsequently OOB. No other force caused the ball into the endzone and OOB therefore it is a touchback. Team A will have possession of the ball after the touchback (if there were no penalties).
2.) Since Team A would put the ball in play next, they must decide on their penalty first (IBB).
a. If Team A accepts IBB
i. and Team B accepts the IF, it would be a double foul and the down would be replayed (A’s ball, 2nd and 10 from B’s 20)
ii. and Team B declines the IF, it would be Team B’s ball 10 yards from the spot of the IBB (B’s ball, 1st and 10 at A’s 45)
b. If Team A declines the IBB
i. and Team B accepts the IF, it would be Team A's ball 5 yards from the previous spot and replay the down (A's ball, 2nd and 15 from B's 25)
ii. and Team B declines the IF, it would be a touchback (A’s ball, 1st and 10 from A’s 20)
Ok, now murder my thinking… In basketball, I would have called a travel before the crash and no foul
