I mean, they hired a third party investigator for it. Short of FOM or FIA hiring someone themselves (which doesn't really have any less of a conflict of interest), there's not a whole lot else that could've happened.
Again, there's not realistically not much more that they could have done. Anyone hired for it is going to be paid for by either RBR themselves or FOM/FIA. There's always going to be that specter hanging over it regardless.
To put it another way, the investigators are going to be hired by someone who has an interest in the proceedings. Either the alleged victim, or Christian Horny, or RBR or FIA, or the tabloids. If [email protected] is that interested there is nothing stopping him hiring his own investigators too. The only difference is the degree of cooperation from the people being investigated your investigators will get based on who hired them.