To put this simply, it was possible to deposit v1.7 DOGE (mined at like 3 difficulty) onto mcxNOW, and then withdraw v1.8 DOGE (i.e. the "real" DOGE mcxNOW owned).

Essentially the entire mcxNOW valid DOGE balance was withdrawn, it wasn't just a case of lots of fake DOGE appearing and being dumped for BTC - the valid DOGE the exchange owned were actually withdrawn too.

This is a little known fact that RS tried very hard never mention - the valid DOGE balance was also withdrawn.