AC coolant on radiator

I bought this car second hand. The AC was in need of refrigerant. I got it filled and they said there were no leaks but it was bone dry. About two weeks later it started to blow hot. When I brought it back in they said the refrigerant had sprayed onto the radiator and quote me $1,800.00 to fix it. I told my father about this (a mechanic a few states away) and he says it sounds like the accumulator gave out, which is a much cheaper fix. There is nothing else that points to an issue-noises, smells, etc. It just blows hot when turned on and has this leak. What could it be?