no time to set

[Mike Simonds]

Don has it correct.

This would be a live ball foul. B can decline the penalty and accept the results of the play. If time expired during the down the period is over.

Or B can accept the penalty and replay the down.

Remember PATIO. Extend the period for an untimed down when:

PA Penalty is accepted
T Touchdown, for the Try
I Inadvertent whistle
O Offsetting (double)fouls