Accepting draw after game ended

So I just played a 3+0 game against a dude that was down queen against knight, obviously he stopped playing at minute 1:30 and just let the clock run down. Just to joke him I offered him a draw when his clock was at .1 seconds and after the game ended and gave me the win, he accepted the draw and the text went from saying I won to it saying draw and giving the points of a draw. I know it was a stupid thing to joke with the draw offer but how is it a thing to draw after a game has ended already?

The first mistake was to offer a draw in a winning position

@TheChessPlayer21 I know that but I also knew he wasn't gonna be able to accept the draw in the half second he had, I just didn't know he'd be able to accept it after the game has ended, I find that absurd.

When an opponent runs out of time and you offer a draw, lichess accept it automatically

I also tried this once in anonymous mode and it was considered draw.
Let's just say, I don't make the same mistake again.

Today I learned something new I guess haha. I used to do this from time to time in chess.com against ppl that just ran out the clock but as you said @PranavBobbySekhar wont be doing it again lmao

So now I suppose the dude you played will be posting that game...