> naming them is perhaps invasion of privacy?

No. The President of the United states is Donald Trump. His address is 1600 Pennsylvania Avenue and his phone number is 202-456-1414.

> Lying however would be slander and illegal…

They couldn't prove he did.

I’d argue that’s rather different than just a cop somewhere.

He said they were criminals, and that the woman was actually a man..

My understanding is he said "Adams county sheriff's are crooks because they took my money" (which is not disputed)., and individual officers, who weren't actually mentioned by name, sued because someone else was responsible for taking the money

> He said they were criminals, and that the woman was actually a man.

If that were defamatory, 90% of QAnon would be in court.