Yeah, they are jewel cases in a clamshell. The jewel cases are glued to the clamshell. The glue does not hold up well apparently. But really, the quality everywhere else shows no obvious sign of bootleg. If it is a bootleg, they went over-the-top to make these look authentic.
What Region are you in? Here in America (Region 1), they were released in trays wrapped in flimsy plastic. I think the clamshell sets were released in Region 2, but I don't know this for a fact.