What they're essentially saying is that its genuine and plays on UK based equipment. Which isn't a lie, it is UK Region 2 (B) but it's not from the UK, I've seen listings like these all the time and its easy to be misconstrued. They probably wouldn't sell as many copies if they said "
This is a genuine Region 2 import".
However, the seller is now apparently proclaiming it to be an Irish copy, which like
@BluSteel2012 said, is phoney. UK/IRE share the same disc, in fact some countries in Europe also do the same. Why the seller would complicate the matter is another story...