A 3/4 @ B-40. At the snap, team A had 5 players in the backfield. B69 intercepts a legal forward tipped pass and is tackled at the A-35. On B69’s interception return, A44 holds B22 at the B-45. With the crown of the helmet, B70 hits A70 at the knees while A70 is on the ground at the 50. Ruling?
Let me give you an example of how I work the questions.
1. Team A commits a live-ball foul at the snap. ("At the snap, team A had 5 players in the backfield.")
2. Team B gains possession before fouling ("clean hands" exception to offsetting penalties might apply). ("B69 intercepts a legal forward tipped pass")
3. Result of the play is team B 1/10 A-35. ("is tackled at the A-35")
4. Team A commits a live-ball foul while team B is in possession. ("On B69’s interception return, A44 holds B22 at the B-45")
5. Assuming that the contact by B70 occurs while the ball is live in team B's possession, this is a live-ball foul on team B while team B is in possession. ("With the crown of the helmet, B70 hits A70 at the knees while A70 is on the ground at the 50.")
6. We now have all the information from the play situation and can proceed with options.
7. Team B has the option to decline all team A penalties to keep the ball, which they will do.
8. Only remaining foul is the TGT by B70, which is basic spot enforcement, and basic spot is the spot of the foul.
9. Result: Team B 1/10 B-35. B70 is disqualified.
10. Possible but extremely unlikely result: Offsetting fouls, Team A 3/4 B-40. B70 is disqualified.
11. Game clock will start on the snap if #9 (1st down for team B), ready if #10 (clock stopped only due to penalty enforcement).
12. Play clock is 25s due to penalty enforcement.
If the TGT happens after the ball is dead, there are no offsetting penalties and team B will likely decline the illegal formation and accept the holding penalty. TGT penalty is enforced after that, so we end up at A-40, 1/10 for team B, snap, 25, disqualify B70. Theoretical alternative is team A 1/10 B-30 after team B accepts the ILF penalty, and another theoretical result is Team B 1/10 B-35 after team B declines both team A penalties.
Do note that this is a bad example as the play situation description does not have enough information for us to fully answer it.