Does this qualify as "sway"?

U-haul tandem axle trailer have surge brakes. Hard braking with this setup can easily lockup the trailer tires, and recovering from that is very unintuitive, because you have to "pull away" from the trailer to make them release at that point. The return spring in the coupler don't have enough push to do anything once the brakes are locked up. And when the driver felt the trailer push, they likely jammed the TV brakes harder.