Nuclear Free

If you have a meeting with 80 invited participants and someone else shows up (with lawyer) who has a history with prior meetings... wouldn't that be a reason?

The requirement for this meeting (unlike what their attorney claims) is that proceedings be publicly available. That could be by transcript or audio/video recording. It wasn't a meeting for public comment or debate (as was laid out in the announcement - again unlike what their attorney claimed). If they have no defined participatory role, then making such records available is all that's necessary. They obviously wanted to be there to put their position forward, and this wasn't the forum for it.

I got the impression they were escorted out before anything started

If they got in at all. It's hard to tell, as their press release is filled with weasel words (such as the nonsense about it being ratepayer funded.