I think that offering to play out a game that you would otherwise resign and deferring the decision to your opponent in case they'd like to play it out (as your friend did) is an incredibly conscientious and classy move.
Asking an opponent to resign, no matter the position, on the other hand is quite the opposite.
In a recent game, a friend of mine posted this in the chat box --- There comes a point where the victor of any given match grows more and more apparent. I don't want to rob you of working on your endgame, but at which point is it acceptable to resign?
I responded that personally, I don't think it's ever unacceptable to resign.
While my endgame could definitely use work, I'll take the win over a long-drawn out endgame where I could possibly blunder away my advantage.
Yet, the flipside of this conundrum is when people ask me to resign in a game when they seemingly have an overwhelming advantage.
That seems both presumptuous and rude to me.
What do you think?