Does the thing being bypassed prevent you from saving the page, or from making in any other way a copy of any content you've already fetched?

If not, how could it be classed as copy-protection?

Edit: One other thing: if spoofing UA headers was a problem, all the browsers in the world would fall foul of it - because non-Mozilla browsers all say that they're Mozilla, and Opera said it was IE, and Chrome said it was Safari, and now a bunch of browsers say they're Chrome - at the same time as saying they're Mozilla. Except it's more complicated than that.