Should have the book thrown at him too. Pathetic behaviour from him and Leeds as a club. The response from the RFL was required, surely Leeds can see that. If social media is making a serious allegation against a player and there is some evidence to support it (As there was with the blowing of kisses and possible video of homophobic words being used) then they simply have to investigate it.
What has happened here is that the lip readers said it was inconclusive and the Saints players refused to give evidence (Not good on Flanagan's part IMO) in support of the player as tends to happen with rugby players, so they've had to go with the insufficient evidence outcome.
I really don't see any room for Leeds to complain about the process. Had the RFL ignored it, it would have made the sport look bad. Perhaps they made the ref change his statement to mention it, if so, so what provided the investigation was completed properly as it appears to have been.