I've got some experience with practical jokes gone wrong so I could have sympathized with Wong if his freak-out had been genuine. It's a very ugly story – you want his inheritance so when you realize your best friend is playing a joke, decide to kill him. What the jury will get caught up on is when he decided to kill – if it was an impulsive thing as it happened, the jury will be less harsh. It really proves the saying that you can never really know anyone, not even your friends.
A very interesting case and a believable explanation, people are unpredictable when scared.