And we've established he's parked up having a brew so clearly the incident wont be involving the vehicle
Exactly my point. An aerodrome is visual so if you are happy that the offending vehicle is clear and will not reenter an active RWY then happy days.
However if a vehicle has been given a blanket clearance or a loose one then you must be cautious of the fact that they may reenter the RWY.
, how often have we seen both Vehicles and aircraft call vacated
if the nose is clear does that not count?