At least according to The Smoking Gun:
http://www.thesmokinggun.com/buster/...nt-hoax-879234
also
http://www.thesmokinggun.com/buster/...op-hoax-869032
I ran across this completely by accident. The original story was thoroughly reported all over the place. Doesn't seem like the truth is as important as the sensational lie. Everything about the story bogus, including the amount of the meal.
The tip was actually over 20%.