The paper you cite espouses a legal theory, not a fact. Who you personally trust really isn't the issue.
Ah, you see when it comes to the application of Constitutional language, there is no such thing as "fact". The closest anyone can come to knowing what the Constitution means is citing the most recent opinion of the most authoritative court ruling touching the issue. Until the U.S. Supreme Court rules on an issue, anyone's statement about what the law provides is just a theory, and even then the statement is only valid until the next case comes along.
The issue here is what legal process fulfills the promise of the Due Process clause of the Fifth Amendment without running afoul of the Seventh Amendment's guarantee of trial by jury. A legal system that entrusts the resolution of complex questions to people who lack the ability to make rational decisions is not Due Process, but a game of roulette.
Bear in mind that the Seventh Amendment only "preserves" the right of trial by jury, it didn't create that right. Since no right to a jury was recognized in 1791 for cases arising in equity, admiralty, maritime law, immigration and naturalization issues, or lawsuits against the sovereign (now the United States government), there is no right to a jury in those types of cases today. Juries can be composed of as few of six people, and verdicts need not be unanimous. In 1791 juries were composed of white men, but today our law recognizes that trial by jury requires a more inclusive composition so that the process of creating a jury pool and striking jurors has been accordingly altered. These outcomes aren't apparent from simply reading the stark language of the Amendment, but they are, in fact, universally recognized to be the law today.
What the law considers to be a Constitutional jury has evolved in the last 223 years, and it will continue to evolve, a process that allows the principles of the Framers to be perpetuated in a world unimaginable in the 18th century. Such a process can't accommodate any notion of unvarying inalterable "fact", but rather must depend upon wise adaptation to evolving conditions. In such a dynamic system we rely upon the opinions of knowledgable experts in each field of law to advise us as to the most likely result were the question to be decided by a court.
Consequently, expert legal theories and opinions are a far more reliable guide to what the law is than any layman's notion of the "facts" derived from simply reading the words of the Constitution.