untimed down?
 

with 15 seconds to go in the first quarter, A 12 holds B 30, and the penalty is accepted. Before the next snap A 2 has a false start. do we still have an untimed down?

NFHS - yes

I'm assuming you mean the clock runs off at some point during the time right before or as the false start is flagged and whistled?

If so, in NCAA, if the penalty is accepted, then yes, there is an untimed down. It wouldn't make much sense to decline the penalty.

Accepted penalty during the last timed down. The FS doesn't affect the fact that the penalty for the hold was accepted, nor that the foul occurred during the last timed down of the period.

Note that the period is extended because of the hold, not the FS.

They are referring to FED rules. In NCAA rules, there cannot be an untimed down after a false start penalty - either the false start happened before the clock ran out, at which point we'd mark off the penalty and start the clock on the ready (unless A was ahead), or the false start happened after the clock ran out and didn't actually happen.