"I think the RFU's moral compass is so high at the moment," Diamond told The Daily Telegraph. "Absolutely, they wanted to make an example out of Denny regardless.
"As was stated in the judgement, there was no evidence apart from the allegation from Jamie Shillcock. There was nothing to back that up. The RFU accused Denny of mouthing it and said it was clearly seen on their video, which the panel rejected. The RFU wanted 12 weeks because they alleged what he said was three times, so they wanted three times four weeks and we got it down to four weeks. We were happy with that but we were not happy with the result.
"Every time you go to a disciplinary hearing what is thrown down your throat are the values of the game. The values of the game are why people play the game at every level, which are what goes on the field, stays on the field. You shake hands. Clap each other off and it all ends. That's gone. The RFU has taken that away from us now."
Sixth-place Sale would rise into the top four should they beat Newcastle Falcons on Friday night and Solomona would be available again for the play-offs. In the meantime, the 24 year-old is adhering to a training plan sent to Sale by the England coaches ahead of the summer tour to South Africa.
Israel Folau has escaped sanction from Rugby Australia for a social media post in which he wrote that gay people would be condemned to "hell" if they failed to "repent". Folau has since deleted the post, but RA chief executive Raelene Castle declined to punish the star Wallabies full-back on the basis of his evangelical Christian beliefs.
Solomona, meanwhile, has engaged in community coaching at Manchester Village Spartans, a gay team, whose members Diamond claims offered to provide character witness statements.
However, Diamond has decided not to press the matter further. "To jump through hurdles and the costs of an appeal won't do Denny, the club or the RFU any good."
Diamond also rejected tabloid reports that the New Zealand born star's visa status was in jeopardy after a supposed "split" with his British wife, Jess Impiazzi.
"It's made up," Diamond said. "Absolute nonsense. All the correct channels of pertaining visas have been done. Jess and Denny are in a marriage and she was in here this morning."