their systems just got overlaoded. It happens, it should not, but they are not liable. That's the law. Anyone posting they are going to be sued does not understand the basics or exchange rules. So stop posting this crap.
Let's see what the SEC has to say about that. Something tells me that if you can't tell someone about a trade you executed at 11:30 am until 1:50 PM, trading should have been halted at some point during those 2+ hours until people were notified that they owned the shares.
Chances are, the rule is in the books, but NASDAQ didn't want the embarrassment of halting trading on it's prized FB IPO, so they just decided to deal with the consequences later.