Would he have won? No. Could he have won--strictly speaking yes. (If white can play with the goal of losing and can achieve it then by definition black must have had mating material to do so.)
There have been a few games where the draw like this is being questioned a bit.
I wonder if the system is trying to balance the likelyhood of a victory in extreme cases like this. Not sure if it is a bug or perhaps just a need for clarification.
Hello,
The screen shot below shows a game I just finished. I had a pawn left and I won on time, but the computer called this game a draw even though I had sufficient material (the pawn). This must be a bug with the program, and I wanted to bring it to your attention.
Thanks,
Charles