I don't really understand Angry Climber, would you have got a slap on the back of the head for saying
"now chaps I see you have the full equipment would you be so kind as to dig me a few step so I can carry on to the top"
or to put it in a less mountain based scenario, perhaps
"I see you've got the cutlery drawer open, would you be so kind as to pass me a knife so I can butter this slice of bread"
I'm still confused as to why this is bad manners.
That bit isn't rude. It might be funny, but it's not rude (actually, it's exceptionally polite in the circumstances).
BUT, it does suggest a bit of a nerve, thinking it's OK to go half way up a mountain and then rely on someone else to bail you out. It's not as if he was acting in ignorance, as if he has all the right gear at home, he presumably knows what IS the right gear.
The rude bits are a) picking someone up on their work so aggressively when they have no obligation to be doing it in the first place. "Would you mind just making that one a bit more level, as I'm not so sure footed. Thanks." would have been better, and b) calling someone "boy", which no matter how you look at it is derogatory as it suggests a master/servant relationship.
Me, I think I'd have said "do you mind not calling me boy please?", "I'm sorry, but I AM doing YOU a favour here, please don't be so bossy", and "I'm happy to help you get down, but not up, so you can go home and collect the gear you've got".
Mark