Philosophically, SHOULD this foul be allowed to carry over? I don't think so, I think that should be limited to personal fouls. But that isn't the current rule. ALL fouls by B on a TD or FG carry over.
So, in general (except for unsportsmanlike and non-player fouls) there is NO situation in NFHS where

Defensive Penalty declined

Touchdown
This happens constantly. I see this all the time. I guess everyone around my area is wrong.
I've always known: Roughing the QB, personal fouls, are enforced on the try or the kickoff, but on many occasions in games, you get a play like this:
A1 drops back to pass, flag thrown on the line, pass caught by A2 who proceeds to run 30 yards for a touchdown. Coach A1 fumes that a touchdown is taken off the board, then the referee signals that the illegal hands-to-the-face is against the defense. The coach cheers, the WH signals illegal use of the hands - defense. Penalty declined. Result of the play: Touchdown. Nary a word by either team about the penalty enforcement.
I guess this is something that now that I know the rule, I'll enforce. But, it flies in the face of what I have known about the rules. Glad I've got this board to understand the rules better.