Interference while Standing on 3B

[bwbuddy]

I had originally posted this on the baseball board, but since the ASA book has confused me, I thought I would post here too (I may be umping ASA this summer).

--- Sitch: R3, 1 out. Batter pops up in foul territory beside 3B. F5 breaks to catch popup. R3 stood on 3B, watching popup as well. F5 crashes into R3 (while standing on base), and can't make catch. Assuming that in umpire's judgement, catch could have been made with normal effort had the crash not occurred, what is the call? ---

Here's what I found in the ASA book:

--- Rule 8, Section 7: "The batter is out when:" J. "When the runner interferes:

1. With the fielder attempting to field a batted fair ball or a foul fly ball, or
2. With a fielder attempting to throw the ball, or
3. Intentionally with a thrown ball.

EFFECT: The ball is dead and the runner is out. All other runners must return to the last base touched at the time of the interference.

EXCEPTION: If the interference prevents the fielder from catching a routine fly ball (fair or foul) with ordinary effort, the batter is also out. ---

I couldn't immediately locate a reference to standing on the base, so any assistance would be appreciated.