Doesn't matter what refrigerant it is,EPA regulations (read when anyone who has a refrigerant usage liscense including 410a) knows any leak is to be reported to the owner of the equipment and should be repaired,properly installed refrigerant systems Do Not Leak,joints can break,lines can rub together causing leaks, other than that if all caps are put on properly you should never have to add refrigerant except maybe every 15 years from servicing
I understand and agree with what you are saying. I was merely pointing out the fact that if his system was using the proper refrigerant that no cfc's were being released into the atmosphere.