Using privacy tools wouldn't necessarily be the smarter move as they could be taken as the smoking gun of someone trying to hide their tracks because they are aware of the problematic aspects.
Do Kwon had virtually unlimited resources for a good plan. My observation from the field (not knowing Kwon but other fraudsters) is that there is an overconfidence based on power. It falls like a house of cards when official prosecutors are involved. It works when everything is handled privately.