I would guess the guy does the same route over and over and your misses car makes his like a bit difficult and so he has got his arse in his hands.

I would make sure you get his details if he comes a knocking and report him if he is unreasonable and a pr*ck as he may decide to accidentally catch/bump her car.

On the flip side though, if she is causing a nightmare in where she is parking then maybe a bit of give and take is needed? I see people parked all the time that are technically doing no wrong but could park differently and make life easier for others, but it is the 'their problem' attitude.