So, looking at the original video:
https://www.youtube.com/embed/FW8A_4dUhMg
Miller has 4,000 customers, and no one is complaining. He is a threat to the large food producers, as he is producing something that people want. He is not tied to gas or fertilizer prices, so his food will not only be better, but more economical.
It looks like the USDA is wanting access to Miller's farm at all times, and that is the problem. This is the same reason they went after the Chickweed Salve Amish farmer. They can show up at your property, without a warrant based on probable cause, and fine you for anything they don't like.
Miller is not selling to the public, he is selling to his "club". This has nothing to do with the USDA or interstate commerce, it is a private treaty.
A $300,000 fine has nothing to do with "correction" of Mr. Miller, but the elimination of him and his business.
The 10th Amendment to the Constitution states:
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
The USDA, the FDA, the FBI, ATF, DOJ, DEA - all of these agencies, are not in the US Constitution, and should operate at the State level, and not at the Federal level. Or else, they need to amend the Constitution.
If you remember the Prohibition of Alcohol, they had to pass an amendment to the Constitution to start Prohibition, and another to end it - as at that time, Congress lacked the ability to operate outside the 10th Amendment.
Because of WWII, Congress created the Dept of Defense without changing the Constitution, and then created the other "3 letter" agencies at the Federal level, all of which violate the 10th Amendment. The 1968 Gun Control Act and 1968 Controlled Substances act - no one ever even thought they would have to pass these as amendment to the Constitution, as they did in the early part of the 20th century for Prohibition.
Although some of these laws are needed, when they are administered at the State level, the average person can object to the law through the State Legislature, or move to another State. At the Federal level, you have very little recourse.