It is illegal on two points: 1. You cannot toss or drop your racquet to make a point, and 2. You cannot touch the net. I've seen this clip before. It's really cool, but it's so short and no context is given. I don't know if it's a real match or just an exhibition. If it's an exhibition, ok. It was fun and everyone enjoyed it - even the opponent. That makes me think it was an exhibition.