It WAS probably the Mossad who did it. I know the man had quite a few enemies but Hamas most mortal enemy number one is no doubt Israel. And it's not like these actions haven't happened before.
U.S. to deliver 8 advanced F-16s to Egypt on July 30-31, U.S. embassy in Cairo says (Reuters)
from the article: Ireland confirms 'Irish' Dubai killers don't exist