On our team? Yes, Kane. I'm really not interested in what a single stats website says. Go have a look at what journalists are giving with their player ratings. I had a quick look and Son was averaging about a 4, Kane was being given a 7. Stats aren't going to show Son mostly being invisible whereas Kane was distributing the ball brilliantly all game and being pretty much our own player showing any kind of consistent quality.
You are alone in thinking he was our MOTM. I dare you to right now go and find me a single actual person watching the game and giving Son a higher rating than Kane. Not some shitty aggregated ratings website, a human being.