I wanna tell you a story.
Vehicle on runway for bird scaring. Seen to vacate onto a taxiway about 2/3rd of way up runway and drive past the holding point. Aircraft already lined up cleared for takeoff.
Vehicle then does a 180, drives back past the holding point and re-enters the runway.
Driver's excuse was he hadn't reported runway vacated. NB: The 'air' frequency is re-broadcast on the vehicle ground frequency.