I keep an eye on the FDA's reports of things that are refused import at the docks. This is far and away the most common cause of problems with regulatory compliance. The goods get looked at by officials and they are able to take action against anything they deem to be wrong by the simple expedient of stopping it entering the country. There isn't a huge amount the supplying company can do when this happens. There is a steady stream of these events but one company seems to have had a particularly bad time in June with no fewer than 7 counts against them.
It is instructive to go through what they got wrong - in six cases they are using a colour that isn't approved under Section 721(a). In the 7th there was no ingredient listing.
I don't know if it was the same colour in every case, but I'd assume that it was. To have a SKU with no ingredient list at all at the same time really does sound like the supplier is very casual indeed - but I think it is more likely that the inspectors simply couldn't find the list. There are some exemptions applicable in the EU so this might simply be that the supplier has assumed the same rules prevail in the US.
So the moral is pretty clear. There are some things you can get away with in the EU that will get you into trouble in the US, and the place you are most likely to run into trouble is the side of the dock. And remember, if you get one thing wrong all the while you are under scrutiny there is a good chance something else will come to light.