Fr. Corapi was not a parish priest, so whatever might have happened could not possibly have involved a parishioner. The person making the accusation was an (ex-)employee.
The BlackSheepDog web site was shut down and Corapi disappeared from public view over a year ago.
Most of the information available about Fr. Corapi's personal situation is unverified rumor, and thus is not appropriate for discussion. Discussion of he catechetical material is appropriate.
I apologize if my comment sounded too negative about Fr. Corapi, that is not what I intended, though upon rereading it that wasn't how I wanted to say it. Thank you for pointing out that it was Black Sheep Dog - I have the image of a canine in my head but got the wrong one. I did read on his website that he (Fr. Corapi) decided to leave the priesthood after the superior's decision. I liked Fr. Corapi but I didn't believe that he was doing the right thing, it seemed to not be in obedience. But then again, I don't have all the information on the case, only God does.