It was dramatic. It was a game winner. And then he did something totally surprising. He made a facial expression that I'm still trying to understand the meaning of. He glared and jutted his lower jaw out while huffing air pretty hard. And I just can't figure out the mindset that would make that expression.
Its a fun game to try to mimic someones facial expressions; it really gives you an idea of the emotions they are feeling. It is a useful tool for figuring out how people really feel about a situation. Words say one thing. The face tells reality. One can pick up on subtle emotions, signs of defeat, of defiance, etc.
And Kobes facial expression? I have no idea what it means.
The closest thing I can think of is that of a wounded animal, or a person who was just tackled and hit but is now on his feet after fighting off an attacker. That same glaring, defiant, but also scared? look.