CHAIRPERSON
It seems that he only comes into the picture and makes common cause with his colleagues at a time when a scuffle had broken out.   He had nothing to do prior to that incident, and he walked in there because he sees a physical development taking place and he joins in.   That is his evidence.  And I think that it is fair to put it this way that if the didn't see the threat of an assault on one of his colleagues, he might not have joined in.   So what motivated him in joining in, was a desire to protect a colleague.
     You invite us to look at his conduct in the broader context, that because he's a policeman,  when he joined in, he was joining in the fight against people in the Liberation Movement, that is what you are trying to say.   Is that not so?