If there were government inspectors how did rotten meat get through?

From the text:

Before the carcass was admitted here, however, it had to pass a government inspector, who sat in the doorway and felt of the glands in the neck for tuberculosis. This government inspector did not have the manner of a man who was worked to death; he was apparently not haunted by a fear that the hog might get by him before he had finished his testing. If you were a sociable person, he was quite willing to enter into conversation with you, and to explain to you the deadly nature of the ptomaines which are found in tubercular pork; and while he was talking with you you could hardly be so ungrateful as to notice that a dozen carcasses were passing him untouched.

One curious thing he had noticed, the very first day, in his profession of shoveler of guts; which was the sharp trick of the floor bosses whenever there chanced to come a “slunk” calf. Any man who knows anything about butchering knows that the flesh of a cow that is about to calve, or has just calved, is not fit for food. A good many of these came every day to the packing houses—and, of course, if they had chosen, it would have been an easy matter for the packers to keep them till they were fit for food. But for the saving of time and fodder, it was the law that cows of that sort came along with the others, and whoever noticed it would tell the boss, and the boss would start up a conversation with the government inspector, and the two would stroll away. So in a trice the carcass of the cow would be cleaned out, and entrails would have vanished; it was Jurgis' task to slide them into the trap, calves and all, and on the floor below they took out these “slunk” calves, and butchered them for meat, and used even the skins of them.