A person on a typical bike would swerve, check traffic, and open the throttle turning to the right and leaving them in the dust.
You guys are ALL assuming this is an 800 pound bike. It's a 300 pound Honda Grom. Max speed of 60. The guy couldn't get away if he tried, at least at night anyways. Had he been on any other bike, the options posted previously were fair game. I don't really see any other option considering he's on a 125cc barely street legal bike.
That's why I laughed at the title "biker"... it's basically a Vespa.