So, following up with PSK qualifying for the "clean hands" exception, try this:
4/3, A-32, 6:30 (4), A=21, B=20. A11's punt is in the air when unblocked A88 runs out of bounds, then returns into the field of play. The ball lands on the ground, and bounds toward B's goal line. B99 pulls A1 to the ground at the B-40, and B80 recovers the previously untouched kick at the B-30. Attempting to elude defenders, B80 retreats the B-25, where he fumbles the ball which is muffed by several players attempting to recover it, and it travels out of bounds at the B-15.
Hmmm. What happens now? Will Team B elect to refuse offsetting fouls to keep the ball (and not risk repeating the down with, perhaps, Team A advancing for a first down)? If Team B refuses offsetting fouls (by declining Team A's penalty), Team A would then obviously decline Team B's penalty, and accept the result of the down, i.e., B,1/10, B-15. Can Team B then change their mind and elect offsetting fouls and have the down repeated?
No. Once a penalty decision is made by a team, that decision is final, and may not be changed. In this case, Team B first has the choice to refuse offsetting fouls (by declining the penalty for Team A's Illegal Return foul) and keep the ball, or they can elect offsetting fouls and repeat the down. If Team B refuses offsetting fouls, then, Team A gets the choice to accept or decline the 10-yard penalty for B's holding foul (which is PSK enforcement, and would be penalized at the end of the kick (B-30), taking the ball to the B-20, if accepted). Since the result of the down is B's ball at the B-15, Team A would obviously decline the penalty.
B, 1/10, B-15.
Now, during our explanation of the options to the Team B coach, we should certainly advise him that, if he elects to keep the ball, he will be putting it in play at the B-15 (rather than the B-20). That may make all the difference in the world to him, and let him make the decision to accept offsetting fouls, and have the down repeated, hoping to achieve better field position, at the risk of Team A advancing for a first down.
In a somewhat complex situation as this, we can't be in a hurry. As a crew, we need to understand ALL options among ourselves, and then explain those to the coaches, before either make a choice. While I would hope that every member of the crew fully and thoroughly understand penalty enforcement, there is usually one guy - maybe not the Referee - that knows penalty enforcement to this level. He needs to step up and make sure the crew knows what to explain to the coaches, so they make the best choice for their team, and they can't blame us for letting them make a bad choice.
Actually had a situation like this happen once. At Fresno State, Fresno was Team B. With the result of the down, they would have put the ball in play at the B-15. Coach, somewhat reasonably, thought they could get better field position if they repeated the down. The other team punted, again, and got a great kick, and tackled the receiver at the B-10.
Things don't always work out. But we did our due diligence, and it was all on him.
Easy peasy.