I say the motorbike taxi guy did in some way try to rob him and that's why the fight started. I mean i wouldn't trust one of those punks under any circumstances, especially when he was up against a drunk tourist late at night.
As for the Bolt driver, i find it hard to believe why the Brit would just attack him for no reason. Again, i reckon the Bolt driver thought he saw an opportunity to make some easy cash out of a drunken tourist and perhaps thought he would jump on the MC riders thieving bandwagon but picked on the wrong guy who fought back and gave him a beating.