Painted leaves? That takes some nerve. I would have lost my mind after driving 45 minutes for that. Always ask for pics of the newest leaf and the stem, not the pretty ones they want you to see. If they won't send fresh shots with a date, walk away.

Something nobody really talks about is how these rules often come from people who were protecting themselves, not you. A lot of the "never do this" advice we get handed down was made for a different situation, a different school, a different time, and it just got passed along like it was set in stone. In my experience the real test is asking what the rule is actually protecting you from, and half the time there is no good answer. Your mileage may vary of course, but that professor sounds like he actually cared about you as a person and not just as a number on a roster. Take it with a grain of salt, but I bet there are a few more of those rules worth poking at.