ADUG definitely IS a related party to City. There's simply no doubt about that. Therefore any transaction involving revenue to or from them should have been reported as such. If ADUG knew that they were injecting funds into City, via a revenue stream attributable to supposedly non-related third party (i.e. Etihad) then that's a related party transaction. If City weren't aware of this, then that's ADUG's problem but uEFA might conclude that, on the balance of probabilities, they were or should have been
While I'm not expert on accounting rules, I'd also say that if ADUG were giving money to Etihad, they were accepting it and passing it on to us, then there's possibly a case for declaring Etihad to be a related party. Which is probably what we should have done in the first place to be honest.