Maybe he saw you and found out you are 6'5" and it intimidated him!
Seriously - some of these guys with zero confidence get cold feet at the last second. I had a blind date several years ago / we were to meet for dinner at a restaurant. I showed up, went inside and waited - and after 20 minutes I just left. I contacted the no-show who told me something surprising. He said he was there on time - waiting in the parking lot and actually watched me drive up and go inside. He said I walked past his car. I told him I saw nobody in the parking lot but an old, fat guy in a badly dented Comet looking at me and paid no attention to him. He then admitted that he was THAT guy. He said he'd misrepresented himself (by about 100 pounds and 20 years) and felt I'd be pissed at him. He was ashamed to meet me, since I'd represented myself accurately and he had not, so he just split - - - leaving me to cool my heels for 20 minutes.
What's with these guys who are no-shows, or fakes, liars, etc.?