This is why I posted this the way I did. It seems that the two rules are at "odds" with each other:
10-4-2 EXC provides team R the enforcement choice (previous or succeeding spot) for fouls by K. The only restrictions I see are that K's foul is not KCI and that K is not next to put the ball in play. Additionally, it does not specify ANY status (live or live ball treated as a dead ball) of the ball when the foul is committed. This play is the latter and carries succeeding spot enforcement (3-7-6). Nevertheless, it seems to me that this live ball foul treated as a dead ball foul should still give R an option of either enforcement spot...
Now, just for the "fun" of it: can a foul actually be committed against a player who is in the game illegally (as above)? B1 enters during the down but is not near the "action". A1 then "buries" B1. Foul?