I was surprised myself how incompetent they can be to make such a schoolboy error.
It'd seem quite scummy to profit from a scenario which results in someone losing their job.
Apprently she was given the wrong rate over the phone, then came over and was given said rate, on the receipt it's also the wrong rate.
If I'm buying some shares and I want to buy at the bid but, being a spaz with the mouse, I accidentally hit the offer I can't phone up the exchange and say 'can you undo this trade please I wanted to buy at the bid but entered a market order instead, it was a mistake...'