If he is used to a TL of FL180 then he must also hear FL200?
FL200 verbalized as 'flight level two zero zero' is certainly a level that you get in the U.S.
However, it was given to the pilots by the tower controller as 'flight level two hundred', that is not something you will ever hear in a U.S. clearance.
Expressing flight levels in hundreds is a common practice in the UK but it is non-standard in Ireland and most other places in the world as other folks have observed here.
And, Americans are just not good with figuring out flight levels other than round numbered ones above FL180. It's a gotcha and we need to be a lot more careful in my opinion.
As I said earlier in the thread:
Many of my U.S. colleagues seem puzzled when I wince at their calls like 'passing flight level twenty-three point six climbing to flight level two seven zero'.