I remember hearing about this at the time. Sklena's clearing firm went apeshit thinking he'd "taken a shot" on massive size so they invoked the "rogue trader" rule allowing them a piece of his profits.
There wasn't much theft in Treasuries. The 5,10 and 30 year pits were pretty much self policing. If you're a trader and you see shenanigans going on are you going to just watch or try to fry someone? It was very competitive-people WANTED someone to be caught with their hand in the cookie jar just so it would free up their monopoly. If anything there were a lot of FALSE accusations frequently being levied. But I got to say if you're gonna do it you might as well go as big as these two did.....