Cat D is minor damage so yes the bumper only, my misses had her 208 rear ended, needed a new boot floor putting in, that was a cat C, that 10 doesn't look a bad buy with the mileage but always has the stigma of being a "recorded" vehicle when you come to sell on, saying that loads of cars like evos have had altercations and are unrecorded lol
May be worth while asking for pics of the damage if available? Also I guess he needed to put it in his name to apply for the V5 as once its recorded as damaged the insurance take the car and paperwork.
Pictures of the damage are a must. No pictures no deal. Then check for quality of repairs and check receipts from the garage which did it. I bought damaged cars and drove them for years, of you do the your homework you might bet a bargain. Still, UK market is bizarre in respect of damaged cars and they do bear the stigma. These days you cannot hide it either.
Its not really even about the repair pictures etc for me, if its as tidy as it looks and the mileage is genuine, its worth that if its not cat D, but it is CAT D, so needs to be a fair bit cheaper for me