A video of a group of young people bullying, jostling and swearing at an elderly man at Hong Kong’s airport becuase he pulled a banner away from a protestor.

Although a video has captured that the elderly man has pulled away a banner from a protestor. But does it really justify the bullying and humiliation by the protestors?
Source:
http://www.globaltimes.cn/content/1159345.shtml
https://www.youtube.com/watch?v=6YFRW7zGD2o