Re:
No matter what the guy on the bike did, it's the driver's responsibility to avoid the vulnerable rider. A 2 ton taxi v less than 100kg bike/rider, the driver has a duty of care to other road users, end of. He tries to squeeze past with no thought for what might happen being so close to bike. If the taxi driver had hung back until there was room to pass bike safely with plenty of room, none of what occurred later would have happened.
The rider was in genuine fear of serious injury, he's going to make his point of view known in a manner that will get the driver's attention. At no point was the taxi driver in danger of injury. There is no excuse for the taxi driver getting out of taxi and waiting in middle of road with fists raised for rider to come within reach then punch him. The taxi driver is a lucky man as there are many people I know, myself included, who would not take kindly to being hit with a swinging fist.