Well, the first time you enter an order by mistake, lets say in after hours and sell shares for 1 c, in a $50 name, lets see if you walk the talk.
I've made some order typos earlier in my trading career and I took steps to make sure they would never happen again. So I guess I'll never be able to experience the scenario you are talking about. My comment still stands: to be fair, US exchanges need to either make all trades stand regardless of price, or allow the counterparty to have the option of an adjustment in price that is x% away from the last trade. The second option allows people not to go bankrupt on one trade, but still makes it hurt so that they will be less likely to make the same mistake again. If US exchanges implemented these rules you wouldn't get situations where people had no idea whether they had positions on or not in cases where there are potential erroneous prices. People could control their risk instead of just guessing because of some idiot with fat fingers.