he did not talk about the inverted value, take a closer look at the screenshot.

I experience this quite often at bitfinex. But everytime I see this, it is just because the trading engine is not fast enough.
So it was like: someone want to sell 100BTC for 200€ , while there are alot orders over 200€ in the orderbook. So the 100BTC sell order is clearing all those orders. But this takes some time and for this time you can see, that the bid > ask.  

But if your example takes longer than some seconds... I don't know what it could be.