Clock and Play clock question

[hear to learn]

Under 2 minutes in the game, the score is tied.  Team A commits intentional grounding and a Team B player helmet comes off (not from a foul).  While I understand the that team B will have the choice of a potential 10 second runoff or have it on he snap, because of 3-3-10-b (helmet it not the only reason we are stopping the clock).  Does the play clock get set to 25 or 40?

In other words does a completion of a foul supersede a helmet off of Team B?

[sj]

AR 3-2-4 V: 1/10 @ A-25. Early in the 4th quarter, back A21 takes a handoff and runs for a 15-yard gain and is down inbounds. During the play, A88 is guilty of holding at the A-30, and (a) B54’s helmet comes off during the play (not a direct result of a foul) or (b) B54 is injured on the play. RULING: The holding foul by A88 will be penalized 10-yards from the spot of the foul and it will be 1/15 @ A-20. In both (a) and (b), the play clock will be set to 40, and both the play clock and game clock will be started on the Referee’s signal.

[Whodatboy18]

From all of the AR I have seen, the precedent is that if the defense has an injury or helmet off at the end of the play, the play clock will default to 40 seconds. Nothing supersedes that except for a team timeout or two minute timeout.

[ElvisLives]

Well, in situations with a penalty administration and a helmet off, there is ambiguity between 3-2-4-c-1, and 3-3-10-b-1.
But, all my sources tell me that Shaw’s intent is that the defensive helmet off/injury governs, and the play clock is set to 40.
I’m OK with that, but fix the rules to say that, for goodness sake. It ain’t that difficult.