For what it's worth, within the period of the last 15 months, I had to fire two Captains (both holding EASA licences, issued by Germany & France, respectively), wherein both were downright bloody dangerous and very evidently never previously in the LHS (i.e. fakers), though the really worrying bit is "where are they now?!".
Imho, there's something very wrong with the recruitment selection & vetting process (and also with initial OCC sim) that such people keep slipping through the net and are only being appropriately questioned (and caught out) when they're into the Line Training (which is when both of the ones that I'm referring to got binned).... but they're still out there, somewhere?!