[alectronic]

The way it was explained in the field manual was that you were supposed to unscrew the tower and bend it over to "normal" height to switch the lights on and off. There should have been enough slack in the signal cord to allow this. But if I had been faced with the same problem, I probably would have reached for the ladder too, messing with taking the pole down just takes too long.
FIRST does supply a ladder on the trucks, but it is not a very big one.