The author suggests this was not a public space. Legal or not, it's more about not being a jerk. I think this is especially important in the context of a hobby,

The author suggests this was not a public space. Legal or not, it's more about not being a jerk. I think this is especially important in the context of a hobby, and the local community around that hobby. There are easy ways for everyone to get what they want in these situations. So, why not get a release? Why not perform some light video editing to cut/blur out people who don't want to be there? These are not high bars to clear. I've done similar things, you have every opportunity to talk to the group and sort this out, and explain why you're filming and where you're publishing. Then people can come to an informed decision...