LoL... that's so weird, because I decided to browse Army & Navy yesterday during lunch for the first time since forever, and I stumbled upon those same jeans and had the same thoughts.
I tried looking up whether there are other references to them selling fake goods, and couldn't find anything definitive, although awhile back people found Juicy Couture goods and were questioning those too. There was speculation, but it wasn't ever proved to be counterfeit merchandise.
It's weird, because you would think a store like Army & Navy that's been around since forever wouldn't have any knockoff products, but those Hugo Boss Select Line jeans can't be the real deal.
I found an eBay listing for a pair of Hugo Boss Select Line jeans, and there are pretty significant differences: Men's HUGO BOSS SELECT LINE JEANS Size 38x34 #2037 | eBay
I saw one pair there had a "Boss" patch above the pocket sewn upside down.