Seems to me that they didn't have the correct rating tyres and fitted what they had in stock. Your handbook will have the correct specification for the tyres for your car in it. If you had an accident through no fault of your own the assessors would pick up on incorrectly rated tyres and your insurance would be invalidated.
Unlikely, very very very very unlikely, unless the tyres were so far out of spec it made an actual difference then this wouldn't happen (and unless someone had been severely injured the assessor would only check the condition of the tyres or if they were nominally right). They might be able to do this on load ratings (but would struggle) but would get laughed out of court on speed ratings alone (unless you'd been on the autobahn).
You also have to watch this as Saab changed the suggested load ratings of some tyres after the car had been released (they did this for the 9-5 estate) as once some tyres got fitted that were the correct load rating at the time but the car subsequently went back to the dealers and a service bulletin had come out of Saab in the meantime and the dealership tried to blame us as the poor specialist for not knowing what we were doing. We pointed this out to the customer who went back to the dealership and asked them about the other tyres they'd fitted prior to this change that were the wrong rating and asked for a refund as they didn't last very long, the dealership changed their tune then.
What we need to know to say which tyre ratings you should have is we need to know engine and if it's an estate/convertible/saloon and the model year. V rated tyres are good for 149 mph, and W rated are good for 168 mph, no Saab came from the factory that could exceed (at least officially) 155mph.
