In my casual match which I played today the result was given as loss because my time was out but black had only a knight. How can he mate me with a knight. It is a draw
You could've checkmated with pawn promotion, so the game didn't end on insufficient material. Draws are actually given for time outs if the player who ran out of time had a huge lead in material, which you did not.
It is only a draw if no series of legal moves leads to checkmate. As proven in #2 such a series exists here, so you lost on time. So that is the right result. If you do not like that, then play with increment.
