I'm not sure. I think it may have been glitching. Because he was using an AM radio (bad imho) and I also noticed that while he was putting the boat in the water, the motor buzzed over for a split second. And, when he was taking it out of the water, it happened twice. To the point I picked up his Tx and held the antenna up just in case it was due to lying on the ground.

So, not sure. It may have been glitching. Or, he may have simply backed off the throttle at those times. This boat weighs around 50 pounds I thought, when I picked it up. So, letting off the throttle is like putting on the brakes I guess!