Quick question - Was it a disconnect in battery or internet?
If it was battery, they you would have completely logged out and "abandoned" the game.
If it was internet, chess.com bases it on the time control of your game. If you do not play a move for a certain percentage of the game, it counts as game abandonment.
I quickly connected in battery but chess.com resigned the game for me.
Chess.com should only make someone resign when it take them inactive for a long time not 1 minute