Luckily the Blue Jays won the game, so the point is moot but here is a screen capture from this MLB video clip - http://m.mlb.com/video/v523212483/must-c-curious-rangers-take-the-lead-on-crazy-miscue/?game_pk=446255 . I find it very interesting that Jeff Bannister knew of this rule because it had been previously called on him as he stated in an interview after the game (probably he was in the minor leagues). It happened so quickly and unexpectedly, and with Harold Reynolds immediately saying it was a live ball and unintentional, that the immediate reaction is to consider it as such. However, by that point of the game, Choo would have seen Martin throw the ball back to the pitcher several times and would have known exactly what path the ball would be taking. It appears to me to be a well timed, crafty move by a veteran player who knew the rule. However, even though Choo was in the batters box he had to make it appear to be unintentional since the rule doesn't allow a player to intentionally interfere with the throw back to the pitcher.
I find it to be very suspicious that the Texas Rangers all knew of the rule and the runner (Odor) broke for the plate immediately whereas almost no one else in the stadium had ever seen such a thing before and the umpire was not sure of the rule.
In any case, I think this play got the Blue Jays fired up and resulted in the Blue Jays blowing the game open in the bottom of that same inning. So it worked out in the Blue Jays favour.