I wouldn't interpret it that way. It seems like the council workers have been out to the flat various times with mixed findings. It might be that they're prone to confusion, but I think it's more likely that the level of noise coming through the wall is just not constant, consistent or predictable. If so, that means two things:
1) The idea that the resident complaining is living through an unending hell of thud thud thud throughout the night might be overstating it.
2) If N&D can be a viable business without being a noise nuisance some of the time, there's probably no good reason why it needs to be a noise nuisance at all. Ergo, the issue might just be that N&D has to accept it has a responsibility to control the level of noise it emits.
The thing that bugs me, to be honest, it the idea of a wealthy business women launching a social media campaign to demonise a random joe, in an attempt to steamroller the council.
The complainant has a right to complain, and they might even have a point. If they don't, there's a process to decide. But they're within their rights either way. And what they get is half of Manchester, plus plenty of people who've never been to Manchester, calling them a cunt on social media, whipped up by a bullying campaign unleashed by someone who is guilty of a much greater degree of poshness than they probably are.