I combed the rules, and though it emphasizes safety (and this act seems to not be very safe, strictly speaking) it does not lay out any explicit rules for the robot->lift->pilot exchange of the gear, other than it has to come up through the hole.
But of note, in the field walk-through videos it seems to say that "once the pilot has determined that the robot has safely put the gear on the peg, they can lift it up and away from the robot" (@0:57 here
https://youtu.be/ZeOevMTC_rw?t=57s).
What confuses me is that this seems to be a significant hole in the rules, as it's the difference between a mostly passive system and a significantly more complicated active system. Though I would not be surprised if the GDC simply didn't think about it, and adds a rule prohibiting lift movement while a robot is touching the gear on the peg, there is a chance that they intentionally left the rule out to make the gear movement an easier task.
Does anyone else think it will be corrected? If so, doesn't it seems like quite a large rules change? Is there a precedent from previous years for a significant change like this?