Did you see the bout? He didn’t shake his opponents hand because the opponent repeatedly grAppled his head. This is against the rules due to the danger. The actions were blatently obvious and the ref chose to ignore them and, despite protests by the australian, only acted after it continued for an entire round by issuing a caution with no points deducted - the Indian ignored the caution and continued to grab the Aussies head and wasn’t pulled up on it. While I doubt he wouldn’t have shaken his opponents hand had he won, the actions of the Aussie were born out of frustration with this rather than xenophobia.