The transmitter will have a VSWR trip for just this sort of eventuality. It would likely be damaged severely if allowed to operate into an open circuit for more than a brief moment.
My first thought also .. possibly pulled a breaker rendering cable inert, or perhaps rigged a remote cutting tool - drop saw poised to cut on a long extension cord ready to be turn on ... (problematic).
I'm leaning toward killed the current first somehow, but very location detail dependant.