This problem is ENTIRELY down to the max cashout idea. It alters player behaviour, and in some cases can cause this kind of problem. The RJ win was considered valid because it was NOT confiscated when processing a withdrawal, it was lost back during play. If it wasn't for the max cashout, the player would most likely have withdrawn near the peak of $13K, and there would never have been any question about him having truly won the RJ.
The best way forward would be to STOP giving out these tiny free chips with max cashout, because it IS possible to trigger a RJ on one of these, even though it's highly unlikely. When an RJ IS triggered, and confiscated, due to a max cashout, the result is inevitably BAD PR for the casino. Free chips can be replaced by depost bonuses, for which there would be NO restrictions, and thus none of these arguments. If iNetBet doesn't want to go to this extreme, make the free chips GENUINE gifts, with NO max cashout restrictions, and base them on a player's past history, and NOT just because they got the code off the newsletter. They could be based on player's deposits, losses, or wagering, and awarded weekly or monthly.
Players can just as easily try new games on a deposit bonus, and players will often try new games out of curiosity once they have been tempted into making a deposit.
As for the different worry about too much bonus money inflating the RJs, itself a consequence of RTG casinos offering large bonuses (not so much iNetBet, but the others), the software could be set so that only bets made from CASH contribute to the pool. Whilst play from bonus funds could win the RJ, it could not add to the pool, and if the software was further altered to offer non-RJ versions of the game, the RJ versions could be blocked when bonus funds are in play, meaning that players could not even WIN a RJ whilst playing bonus funds.