Wow.
I mean the level of cluelessness here is astounding.
I can't imagine anyone not getting pissed at you
You're 15 minutes late and you cancelled "out of respect for him" ??
No you didn't. You Fucked up his schedule so you could get your full time slot.
Completely selfish move.
Yes ‘giving him his time back’ is kind of not the thing he’d want. That time has already gone and he’s probably spent time preparing and booking the hotel etc. All of that wasted. He certainly wouldn’t see it as having the time back!
Last minute cancellations are very annoying indeed: it’s impossible to schedule anything else and you’ve already committed time and money (probably) to the session and you’re out of pocket if you didn’t take a deposit. I’m not surprised he was annoyed.
You should have messaged him to say you’d be late, turned up as soon as possible, and of course paid him the full rate even though your session was shortened. Sometimes if a client is late and I can move the session I’ll shift it all back by 15m but that’s only if possible and for a regular.
If he is ok to accept another booking then I think you should pay a deposit when you book because I expect he will be reticent to commit again.