The 142 point check in reality probably involves the apprentice wandering quickly around the car with a clipboard to spot if anything dreadful is wrong with the car, then a diagnostic scan for fault codes.
There was probably something flagged up with the electronics so they had to go digging, or possibly just an electrical issue like a mirror not folding properly or a window not opening or closing as it should, central locking issue, ambience lighting issue...
There's no way a dealership will spend a penny more than they have to when they sell a car so they'll rectify any serious faults flagged but won't go digging for any, and certainly none that won't be covered by VW UK as a warranty claim.
The onus will be on the owner to come back and moan if there's something wrong, then the sales team will have to argue their case with the workshop team as to who's paying for the time and parts cost.
The 142 point check is just a safety and general appearance check to make sure the car is roadworthy and fairly presentable.