Stop loss orders are not a panacea here. You could lock in a loss for no other reason than the market becoming very volatile due to some news item or some other reason like the flash crash. And you can't even guarantee to limit your losses at the stop loss price. It's just the price that triggers an attempt to unwind the position.

Also, the market may not go against you immediately. What if the glitch in the system means you're opening positions in stocks and you drive up the price by doing so? The losses are not immediately apparent. There's no screen where you could watch your losses run up in real time. The losses only become apparent once you try to unwind those positions and that's the case in many kinds of scenarios.

I believe it took J.P Morgan months to unwind the London Whale positions and really know what losses were incurred.

I think there's a better chance of catching a glitch at the point where the positions are opened.