Im sorry you ran into such a jerk. No one deserves to be spoken to like that. I may not know you personally but from your posts ive read and the messages we've exchanged I know you really are a good and caring person.
I hate how people fly off the handle. If that man had concerns about you parking there he could have always politely questioned you. This just serves as another example of what a good person you are.. had it been me id have beaten him with my crutch and then yelled "here! now you too can have a valid reason to have the damned spot!" I know. Im mean. I give what I get.
Seriously though, you are a wonderful and caring person who had every right to park where you did whether that jerk wanted to acknowledge it or not.