Errant Throw

[DG]

Fed situation, Runner on 1st and 2nd. F3 playing behind runner. F1 steps toward 1b at same time as F3 starts move toward 1B, timing play perhaps. F1throws the ball into the ground about 20 feet from the mound, it rolls towards F3's original position and comes to a stop in the infield grass. F3 runs over and picks it up. Runner on 2B advances to 3rd. Runner on 1B does not advance.

J/R says "an intended pickoff throw (in contact) to first base that slips is a balk if it does not reach the foul line or a fielder within reach of a tag attempt at the base. I see nothing in FED on this. 10-2-3g situation perhaps. Does an unofficial OBR interp have a bearing when there is no FED interp for a 10-2-3g situation.