A term that recognises that where there's one financial problem, there's usually many more hiding. This is no doubt based upon long experience that if one issue has been discovered that is worthy of concern, undoubtedly there's many more hiding away under the carpet.
Horrible, unclean, nasty - stamp on them with your foot and they make the biggest 'crack' imaginable. Not lawyers, but Cockroaches. They hide under carpets - and when you find one, there's invariably lots of them. It's the same with massive financial scandals - if you find one, then there's bound to be a lot more you just haven't spotted yet.