retired BR

[jmkupka]

R1 on 3B, R2 on 1B, no outs.
Looper to shallow RF. F9 bobbles, then corrals it in.

Fires to F3, who dives at 1B and tags it with glove.

R2, in no-man's land, gets doubled off 1B by the appeal throw (very close play).

BR is standing on 1B as the throw comes in.

If (IMJ), BR's foot blocked F3's access to 1B, would we have a retired runner INT, R1 out?

Or is retired BR handled differently than retired R?

(I'm guessing, if BR stepped off the bag, toward F3, to block the glove touch, it would be a no-brainer INT)