Case Play (ABL Ejection): Stepping Over the Line

An umpire's out/live ball in play vs. dead ball call sparked an ejection in the Australian Baseball League this weekend as 3B Umpire Neil Poulton ejected Adelaide Bite Manager Brooke Knight for arguing a live ball call in the bottom of the 5th inning of the Heat-Bite game. With none out and two on, Bite batter Chan Moon hit a sacrifice fly to Heat left fielder Tim Smith in foul territory, Bite baserunner R3 Rocky Gale scoring as R1 Michael Miller remained at first base. At issue was not the validity of the out (catch) call, but whether F7 Smith "fell" before throwing the ball back into the infield and keeping Miller at first base. The ground rules for the Norwood Oval specify that an out-of-bounds line shall exist in the corners of the outfield, in front of the bullpens, and that a fielder or ball crossing this line shall be deemed out of play.

Momentum carries F7 across the OOP line.

The ABL uses the Official Baseball Rules; pursuant to OBR Rule 5.10(f), "When a fielder, after catching a fly ball, falls into a bench or stand," the ball is dead. However, "If a fielder after making a catch steps into a bench, but does not fall, the ball is in play and runners may advance at their own peril." Rule 7.04(c) specifies that each runner may advance one base when "A fielder, after catching a fly ball, falls into a bench or stand, or falls across ropes into a crowd when spectators are on the field." Rule 6.05(a) Comment similarly states that the "ball is in play unless the fielder, after making a legal catch, falls into a dugout or other out-of-play area, in which case the ball is dead." Replays indicate F7 Smith slid and caught the ball in the field of play, appearing to regain his footing before stepping over the out-of-play line (see attached photograph).

Q: Does this constitute a "fall" under Rule 5.10(f) or a "step into a bench"? Is a bullpen a bench?
HINT: MLBUM #24(5).
Case Play Note: Yes, the 2014 UEFL season has concluded. However, up to two Case Play points for the 2015 UEFL season may be gained through contributing to this discussion.

Wrap: Perth Heat vs. Adelaide Bite (Australian Baseball League), 11/15/14
Video: Sac fly to LF gives Bite a 3-1 lead and fireworks, too, on question of Smith's status (ABL)