I'll respond to my own post since its already 9-0, they're reviewing an obvious play and curiosity got the best of me. You don't become an "old timer" without rambling.
I think I'm right as RBI is defined in 10.04
(a) The official scorer shall credit the batter with a run batted in for every run that scores
(1) unaided by an error and as part of a play begun by the batter’s safe hit
(including the batter’s home run), sacrifice bunt, sacrifice fly, infield out or
fielder’s choice, unless Rule 10.04(b) applies;
(2) by reason of the batter becoming a runner with the bases full (because of a
base on balls, an award of first base for being touched by a pitched ball or for
interference or obstruction); or
(3) when, before two are out, an error is made on a play on which a runner from
third base ordinarily would score.
(b) The official scorer shall not credit a run batted in
(1) when the batter grounds into a force double play or a reverse-force double
play; or
(2) when a fielder is charged with an error because the fielder muffs a throw at
first base that would have completed a force double play.
(c) The official scorer’s judgment must determine whether a run batted in shall be
credited for a run that scores when a fielder holds the ball or throws to a wrong base.
Ordinarily, if the runner keeps going, the official scorer should credit a run batted in;
if the runner stops and takes off again when the runner notices the misplay, the
official scorer should credit the run as scored on a fielder’s choice.
I simply don't see anything in there that says a foul pop up that was dropped elliminates the batter's ability to be credited with an RBI upon completing his AB. A-1 comes the closest, but it says play started with safe hit, which doesn't apply because the batter in question wasn't safe due to a batted ball.