[greymule]

Just to be sure, in Fed:

In determining fair or foul, we go by where the interference occurred, not by the position of the ball at the time of the interference or where it lands or where it rolls.

And once the interference has occurred, whether or not the ball is caught is immaterial.

This from the J/R, which of course applies to OBR only:

Bases loaded, no outs, 0-0 count. The batter hits a fly ball that will come down along the third base line between third and home. The plate umpire signals "infield fly if fair!" R3 then interferes with the third baseman on his attempted return to his base. The ball (a) is caught over foul territory, (b) is uncaught and becomes foul, (c) is caught over fair territory, or (d) is uncaught and becomes fair. The ball is dead when the interference occurs and R3 is out. However, even though the ball is dead, the batter/batter-runner's status is determined by whether the ball would have been fair or foul. In (a) and (b) the batter goes back to bat with a strike added to the count. In (c) and (d) the batter-runner was out on the infield fly before the interference occurred; R2 and R1 return to their respective bases with two outs.

Apparently in OBR fair/foul is still an open question after the interference.

By the way, if anyone wants an example of careful, accurate, precise, unambiguous writing, check out the J/R.