Well, [electrical trim] was cut out by the pilots. They had the option to re-trim the aircraft using electric trim before hitting the cutout..
Yes, it is sure. We know this because MCAS drives the stabilizer using the electric motor, and MCAS dialed in another batch of nose-down trim AFTER the pilots re-enabled electric trim and blipped the column switches (which had negligible affect on stabilizer position).
That the electric motor drives the trim in one direction, does not mean that it is capable to drive it in the other direction if loaded. Think about tightening a vice.