Both are at fault.
Onus is on the Malay guy to signal and check lane clearance before filtering. But I think it's an honest mistake that I've committed before: signal, look in the rear view mirror and then turn your head to check, but still miss the oncoming car because it's in my blind spot. So I get honked at, apply the brakes, and wave an apology. Accident averted, the honking car moves on. No big deal.
This Chinese guy didn't have to stop his car and let loose his tirade. And of course, the Malay guy asking for a mano a mano by way of retaliating is downright childish.