I think that's more of a indicator that it hasn't effected their business. They lost nearly 1/5 of their stock price after that incident (obviously not accounting for other factors; I'm not a stock analyst). Investors thought they'd lose customers and reacted in obvious fashion.

But it's since been restored. According to the news, they lost very little customers over the incident. That is why their stock came back. If they continued having problems, I doubt it would have been so rosy. So yes, to your point, a blip here or there happens.