A/P Disconnect
I didn't mean to infer that the pusher worked through the A/P.
I don't know anything about Challengers, but the Gulfstream pusher could be disconnected at any time with a push of the A/P disconnect button.
It was one of the required checks.
In this landing, it doesn't look like they would have even had time to push the button, and from another poster, over riding the push manually would have been very difficult.