I thought I was coming across as quite adult about it. I said something along the lines of "I don't really feel a connection, and it's also important to me to find someone with the same values around money as me". I don't think I sounded like I was talking down to him. It could have been the part where I asked him about his goals and he was a bit vague, so I said "What about financial goals?" and said he wants to get a house someday and the banks will soon be letting you buy a house with a 5% deposit and I said something like "Oh god, don't borrow 95%, that's way too risky, if the value drops and the bank decides to call it in you'll be screwed". Then he asked what would be a good amount, so I said I wouldn't put down less than a 20% deposit because it's safer. Maybe it was the way I talked.. the same way as I talk jokingly to friends in a colloquial way.
I did think about it afterwards and thought maybe he got offended, so later on that night I wrote him an email saying that I hope I didn't come across as rude and implying that he wasn't good with his money, because I didn't mean to imply that at all. And I said the main thing was I didn't feel a spark, and I wished us both luck in finding someone. That's when he replied saying what I said was rude and hurtful and said about the high horse thing. If he felt that way when I was talking to him at the time, why didn't he say something, like "Oh, that makes me feel a bit stink". I thought it was an amicable conversation and ending, and there was no indication he was upset. If he'd said something at the time instead of seeming to be agreeable and like he got where I was coming from, I would have apologised and changed the way I was talking about it.
Even if he was in a similar financial position to me, there was still no spark, and that was the biggest thing. I don't really have a list.. the only major things to me I think would be the money thing, the connection and if he wants kids. Oh, and probably being not too much taller than me..