How do you know the player isn't up to something intentional, for instance triggering some kind of 'outside investors suddenly acquire all of a stock or bond that we think is going to tank in the next five minutes'?

Are stock market players not allowed to divest extremely suddenly, to dump their property at fire sale prices in order to get rid of it at what would be a paper loss, all the while knowing the consequences of holding would be worse?

What if they're dumping equity in a company that will be known to have committed terrorist acts? I'm not sure if I buy 'clearly erroneous'. I also don't buy that the scale of the error was really threatening to Goldman Sachs.