There are also medical reasons to not drive - epilepsy, insufficient depth perception, etc.
But there were clearly failures to communicate - who was buying, etc. P
Add on the cash flow problem, the inconsistencies (no money, only $60, not enough credit line to put it all on his card, and the pitcher of alcohol) - definite signs of a problem child.
While I believe the OP would have been prudent to either be financially prepared (and just see it as a lesson in red flags and clarification), not having been was not rude, just possibly unwise.
And going back to cover the tip was exemplary.