that's not how limit orders work...if a limit order was placed, the best available price would have been filled, which would have been the bid price at that time...
"Someone typed 3.185 instead of 3.815 (switched digits) for a limited sell order. Makes sense because the PPS was at around 3.80 then. Then it got executed immediately.
As I said, an expensive mistake for more than 300k shares!"
It does not work like that. System will sell at highest bid price even when ask price is low. May be there was some irregular things happening.