[kenshiro_o]

So why did they not think about this possibility in the first place? If they had some simple checks that made sure for instance that the standard deviation was not too high then this kind of problem should have been avoided, right?

Kudos to the players who exploited the loophole. I mean that's how a lot of individuals make money in real life.

[UnoriginalGuy]

According to the story the person literally cleared the market out and then re-listed it at a new price.

Standard deviation won't help you when there is no deviation at all.