Packers can manipulate markets. Pickett prove that. Whether they do it all the time or just selected time periods of their choosing is another question. Pickett did not claim that Tyson manipulated the markets or broke the law all of the time. They did prove that it was manipulated at certain intervals. The argument that they could manipulate them all of the time, or that it would be in their best interest to do so shows how little you know about the markets.
During the manipulation periods, their margins increased. Even Agman admits to that.
Jason, when you were cheating on your tests in school, did you do it all the time, or just when it was advantageous to you? If the teacher walked by did you stop cheating a little until she walked by? If you knew the answer to the question you were working on, did you cheat on it or just answer it?
Even though packers have the ability to manipulate prices, do they do it all the time or just when it is strategically beneficial? When they want to "put the screws" to a competitior, they might do everything they can including lowering their margins, to out compete a rival. Does this mean that they will lower their margins all the time? Of course not. If they do have a strategic reason like running out competitors they will be more likely to decrease their margins, even to negative margins, to run someone else out of business? Of course. Is some of this just plain old competition? Yes of course. How do you differentiate? READ THE PSA AND UNDERSTAND IT AND YOU WILL KNOW. The PSA is an economic law to address the question. Who has the final say as to whether or not it is being done? Juries. They decide all the grey area.