Tell him to get fucked. Tips are optional...not mandatory.
Eat at McDonalds then.
Him chasing you down was wrong, but i find most tech people cheap as hell and have no clue since most have not worked a service industry job.
I have Bartended for 20+ years as a second job. My paycheck every 2 weeks is zero and i actually owe normally $400-$800 a year to work there since they tips they claim off sales does not cover what the $2.62 a hour check does for 2 nights a week.
I am fine with anything as long as people leave something. I worked doing some networking stuff when i was younger and it was amazing when we went to lunch 90% of the people we went with would toss in say $8 bucks for there lunch, when there burger was $6, pop $2. So not only would they not even tip, they would not even cover there own tax when it was all billed in one.
I have a lady that tips me $500+ a night when she comes in when she spends $100 or so total, i have people that give me a quarter on a beer, i treat both the same.
The people i can't stand are the pushy, loud, cut in front of other people then don't tip on $40+ rounds. Its cool though they do it once then wait next time, the beauty of working in a club with 1000+ people there a night.