I think you will find that sadly if you are football supporter your rights get treated rather differently than other people's and the plod can do pretty much whatever they like.
I understand why this is but some police seem to see it as a free hit to act up (some, others are probably far too lenient!)
Not talking about the video, but as a conductor I will obviously deal with large groups, or drunken passengers differently.
Same with passengers requiring assistance, you use different techniques to make your job easier.
Do I talk more abruptly and assertively to drunk passengers, absolutely.
Do I engage in banter with football fans when jovial, but use a more aggressive tone when they are abusive and threatening, of course.
I am on the fence regarding having a body-cam purely because I have never had a situation that I haven't been able to handle, I know many train crew who've been assulted but I also know their character and why it may have escalated that way.
They don't resolve the potential confrontation for those who can't handle the situation in the first place, they are not a deterrent, just a way of collecting evidence.
It always amuses me that RPMs/(Is) tend to work in packs, never alone, yet conductors always work alone when doing revenue.
A good Conductor is no less at risk that an RPM just because it's just a penalty notice.