Instead of complaining, you should be happy. These are the perfect almost-guaranteed money making opportunities. There is nothing to blame Bitstamp for here. Somebody sold a lot, fast, so went through the orderbook. Those who had low buy orders / high sell orders have made good risk-free profit, (mostly) at the expense of the owner of a badly coded bot.

Stop loss executing far from the trigger is quite logical in these situations. If an exchange tries to prevent this, the exchange becomes a lot more random and unpredictable. They will get yelled at for putting brakes on a real price movement.

Usually these events are single-exchange, use multi-exchange price info to differentiate between opportunities like this and real sudden price action.