Some authority should demand all the data from GG to start a proper investigation.
For example, when did MoneyTaker69 register his account? Did he ever change his username?
Regarding leader boards, i'm micro stakes player so i won't be on there, but imagine you are number 6 and MoneyTaker is number 1, then i think its reasonable to correct that so that you become number 5.
I'm part of a Dutch facebook community for GG Poker and i mentioned this incident multiple times but don't get much reaction. Only one Dutch player confirmed he got back .63 cents. He's offended by this and claims that because of he got cheated he often went on tilt, losing much more money. It's hard to calculate how much but i think GG should take blame for this and refund more generously. After all, they are responsible for the safety of all players.
Last but not least i feel part of the blame is for the Dutch government, as they officially allow GG but not Party and Stars.
More than 10 years ago Party was legal in the Netherlands and i remember i made $200 in two years starting with the minimum ($10). Just slowly building bankroll. Now compare this to GG these days and i feel a great difference. From 20 to 0 3 times in a row