Hard to say.

There was a giant concrete pump working near a field I used to fly at. They have remote/radio control units so that the operator can get down off the truck and see where his nozzle is pointing.

Turns out they are on 72mhz or close enough to it, that the comcrete pump was causing problems. The truck was about 3/4 mile away. We lost several planes on different radios and different channels while that pump was working. Wasn't untill AFTER he left (a week or 2 later--big building) that we realized what had happened and someone looked into it to satisfy our curiosity.

DOH!! It was most likely the pump.

It's hard to say what happened to your plane. Could have been the battery. Could have been a loose crystal. You DO tape your crystals in don't you? Could have been interference.

It just took off and then rolled inverted? Augered in?

Did you have the ailerons reversed?