If that happened in the country that I'm in, I can guarantee you that the motorcyclist would be seen as the "victim", and the person who put the chain there would be the one punished. Having said that, I used to have an "open" motorbike license, and would sometimes break the rules too, but I would have NEVER been so stupid as to go through those barriers without a very, very high degree of caution (not just for chains but also for change in surface etc. I would have done it at walking pace. Does that make me better than the idiot in the video? NO - IT DOESN'T! Shame on ME! Truth be told. I no longer hold an open MB license because I've been to too many funerals, and knew from knowing thyself, that I was "next". It's not "wrong" to ride a motorbike, but please, take all the care you can. <- I mean that!
(EDIT - Just to fill in the blanks, in my country an "open" motorcycle license means you can legally ride any type of legal bike of any engine capacity or horse power. I had a 1250)
I am very sorry you had to stop riding. If I am not on my scooter every 2 or 3 days, I go through withdrawal symptoms.