IMO anyway it's inaccurate to think of a pawn being replaced by another piece (I mean, it is physically) but by the rules (especially evidenced when having 2 queens) the pawn's movement ability is "promoted" to that of another piece.
So you're literally promoting the pawn.
Even if he ran the clock out there wasnt sufficient material on the board to mate with. Doesnt matter that a pawn could be promoted, at the time the clock ran out the material was not enough to mate. So even if your clock ran out it was still a draw due to insufficient material.
That doesn't make any sense. If a legal series of moves could create mate, then it's considered sufficient material.
The only exception may be lone king vs two knights which you may have to claim as insufficent losing chances or something.
you are the one not making sense. It's not about " a legal series of moves",it's about what's on the board at the time. A pawn is a pawn is a pawn,and it's nothing more,unless you promote it. If the pawn hasn't promoted,you can't say "well,after x moves it would have", it's a pawn,and it will be treated as such. Therefore,it's not enough material to mate.
Well anyway, I'm not discussing it, I'm just letting you know. You're free to use whatever rules you want with your friends / at your club.
At my club it's not uncommon to give the option of a takeback if the move is inordinately terrible
(you don't ask for it though). We also do clock move instead of touch move.