Hi,
I'm not sure about the whole rooftop thing, but from a different perspective. I think that the whole thing was wired to the studio downstairs, in order to not take so much equipment upstairs, and just keep the rest simple ... if something like this is possible.
For all intents and purposes, that the police stopped the show is not surprising. Remember that at the time, the Beatles were huge, and some thought they were more powerful than the Queen and such, for example, and that they thought they could do anything they wanted ... but in the end, they had to work by/with all the rules and their playing was cut short.
I would love to hear more about this from Ringo or Paul, but I don't think they have ever said anything about it. I also find it distressing that they do not insist on this film getting cleaned up and remastered and released again. It is a documentary that is simply the best look at the Beatles anyone will ever see ... and you can even learn as a young musician, how a song comes alive after some work with everyone, something that most musicians do not like to show or do with an audience. These moments are golden in the film.
This film, for me, is about learning to do your own work ... and as such it is a very valuable experience for many of us ... sometimes it does not start right, or is missing something, but you work it some more, and it comes around sooner or later. It has been a very important document for me, although my own work comes in bits and pieces, and they seem to work themselves together sooner or later. When the feeling and the time is right.
A couple of special moments ... John and Yoko dancing ... that is truly awesome. The other one is George talking about playing live and just kick start it. And of course, they did with the rooftop. Probably thank George for that one!