Again though, he's still got a brand new game and he got it for five quid (kind of) instead of the ten quid he was going to pay. He's actually come out of this deal pretty well!
I'm not sure you'd do anything differently in Game's position. The options they have are to sell the games as new (which they are) or sell them as pre-owned because they changed the case over and lose the money on them. They're probably going to lose more in "pre-owned" discount than they will in goodwill discounts, so they're going to carry on. Their website probably doesn't allow for them to differentiate between new and pre-owned and a new third option somewhere between the two.
If people are really offended then Game have made it pretty clear that they'll happily refund or come to some other arrangement, their customer service has been really good about this. If you're worried because you're overseas then you're better off just not buying from Game at all rather than complaining when you get what you were warned you might get.