Scott,
Actually Fred was holding the plane. Since I am running in governor mode, the startup is very slow (governor mode was made for helicopters, so a slow spoolup prevents the gear in the transmission from getting stripped).
One time I was using my "real stooge" (not Fred "Larry" K.), and I failed to latch the plane adequately in it. There is a 20 s delay from when I push the "go" button until the plane starts to spool up. But anyway, when the motor started to come up, the stooge released it prematurely. So it does a little taxi until it gathered enough airspeed to take off. However on grass, a bad bump and you could be looking straight at the prop coming at you! So normally I signal Fred (or pull the line on the stooge) when the rpm sounds "right". We obviously need a little more practice this year to get my signal to Fred correct, because I waved my hand about something, and Fred interpreted I wanted him the release the plane! It was a little on the low rpm side when he released it.
With my 1/2A electric, the motor comes right up, so I can simply push the button and get out to the handle and make a nice takeoff. You still want a stooge, because it is easy to get distracted and forget that you have a "live" one back in the pits.