The grubs which stole it must have had the keys. Either the owner left the vehicle unsecured, and you would be surprised how many do that, you know, just pop inside for a piss whilst washing the car, or leave the keys in it because they live in the country and it is safe out there, or the grubs broke in to their house/shed and found the keys inside, again fairly common, so don’t leave your keys out on a bench at home. Shame though, nice vehicle. Hope they had insurance.
KB