[kirtar]

It depends, but I'm inclined to say it's not. If your robot was to turn, while the trajectory would change. It may not remain in the same location relative to the robot because it is probable that it will slip and/or roll and stay in roughly the same position that it was (absolute position). Its kind of like pulling a tablecloth from under a bunch of glasses. In addition, if you were to back up, the relative position would quite obviously change. I'd say this one would need to go on Q&A, although I'm not seeing a way to do this well because of the whole bumpers thing.

The reasoning used would also imply that in the instant that a ball lands on your robot off of a short fall such that it rolls off of your robot that it will be counted as carried. In other words, as long as the drop is short, it implies that you carry the ball for an instant in time whenever a ball for example, rolls of the platform and onto your robot regardless of a design to make it fall off.