I think Neville makes a great point regarding Clattenburg resigning over this. It will be interesting too see if he does or not but the fact the tweet has not been deleted as of yet(and these things usually do if the club does not want to be associated with it) suggests even more it's came from the very top of the club and not just some angry Forest supporter doing the clubs tweets.
The owner also owns Olympiakos and if you know anything about Greek football and how clubs push back on officials then this would be right up his alley.