asking on behalf of my ex, and any legal advice too would be greatly appreciated.

She's got a 98 Fiesta Zetec, just put it in for MOT and been told it failed on the emissions. They rang back later to say the engine had blown up (her words) and i later managed to get it out of her that the piston rings had blown. Could they tell this without taking the head off? They offered her £50 for the car scrap and have given her a loan car for free for a week (which seems a bit wierd in itself). They've just done a £290 service on it last week, now theyre saying the engine has blown up?

does this sound right and if so are they in any part responsible? could they have been revving the nuts off it tryin to clear it out?