So let's set aside the possibility that K's touch was in the expanded neutral zone and thus disregarded by rule.
The easiest way to process this play is to focus on first touching and the conditions under which R loses the right to take the ball at the spot of first touching. There are 2:
- R fouls after touching the kick, or
- The penalty for any foul committed during the down is accepted. 6-2-5
(1) does not apply here, since R never touched the kick.
That leaves (2). Since R fouled, K has the option. If K declines the penalty, then (2) would not apply, and R would get the ball at the spot of first touching.
If K accepts the penalty, then first touching is nullified. Thus we have a scoring play by K with a live-ball foul by R. By 8-2-2, the score counts, and K has the option to take the penalty for R's foul on the try or the subsequent kickoff.
So the "other half" of you have the right ruling, but not the right reasoning. Make sure you know when the right to take the ball at the spot of first touching lapses.