vectra problem (not mine)

[madads]

Right I've just had a txt off my cousin about his vec " Car went to vauxhall and timing chains done yesterday (happy with the job). Gets in the car at the garage and starts the engine, where the mileage shows on the display AIR BAG comes on then goes off? Its not the warning light adam... they say its just checking the system, didnt do that before though and my mates doesnt do it either. THEN i get the car home and the f**king drivers windown drops into the door. I take it back and they said on visual inspection they had noticed the window was stuck. I kick off with them and end up telling him to f#@k off and leave the showroom £613 down and 2 possble faults on the car that it didnt have when it went in....GREAT...so i'm getting window sorted but i'm wanting to know about the AIRBAG issue"

So from this can anyone help?
Cheers for any info.