If two people disagree and you're agnostic/disinterested that's fine so long as the two people have comparable power.
But that wasn't the case here.
But then they turned on her for the rest of the match, directing slurs in her ear, tapping her on the head and telling her not to go to the rugby again.
A group of 3 guys, sitting above a woman were being abusive to her - that's bullying plain and simple. I can understand that people some distance away won't see or hear it sufficiently to know how it's really going on, but if one sees that kind of bullying going on and is indifferent to it, that's condoning the behaviour.
Speaking up is a separate thing. You could see it going on, think it's not on, but be too afraid/uncomfortable to speak up. That gets back to Emma's point that in that situation people often don't feel safe enough to complain. It's hard to speak up to a group of usually drunk guys, "What you're doing isn't on." because there's always the risk they might get violent or simply more unpleasant.
I hope the new venture works out well Keith.
I'll miss your presence on PA. I find your writing to be a bastion of intellectual integrity and wit (*hmph* data *hmph* facts. A Jedi wants not these things!) in a world of poo-throwing monkey journalism.
(The budget lunch just won't be the same...)
Good luck on the next big thing