Once Again: What Is Evidence?

Lillie v. United States, 953 F.2d 1188, 1190 (10th Cir., 1992) (civil action; view by judge; footnote omitted):

We acknowledge that jurisdictions vary as to whether a view is treated as evidence or simply as an aid to help the trier of fact understand the evidence. However, we believe such a distinction is only semantic, because any kind of presentation to the jury or the judge to help the fact finder determine what the truth is and assimilate and understand the evidence is itself evidence.

Question 1: Under this formulation, is the opening statement or closing argument of counsel "evidence"?

Question 2: If not -- the law is that such matters are not evidence -- why not? Consider a further question in response to Question 2: Are charts and diagrams, when presented to the trier, that serve only as visual aids -- charts and diagrams that seek to clarify other evidence -- "evidence"? Does it matter whether such "demonstrative" material is presented to the trier during "proof" or whether it is, instead, shown to the trier during closing argument or the opening statement? Should such demonstrative material be shown to the trier only during the opening statement or closing argument? (This would be an unwise restriction, no?)

Question 3: Is expert opinion "evidence"? (The law says that it is.) But isn't some expert opinion just (fancy) "argument"? If so, why aren't the statements of counsel during closing argument treated as witness testimony? Is it because we expect and want trial lawyers to lie (i.e., to make assertions they do not believe are true) during this phase of the trial? If so, what about the assertions of counsel in their opening statements? (Opening statements, the law usually proclaims, are not to contain "argument.") Should counsel be sworn to tell the truth during their opening statements and be prosecuted for perjury if they knowingly fail to do so?

Would it be better to ignore the question of what is and is not "evidence"? (Should we ignore the tyranny of the label "evidence"?) If we did that, it would still be necessary to decide which of the legal restraints and controls that we now place on "evidence" apply to the thing or process whose legal treatment is in question. (A vast number of constitutional and nonconstitutional legal rules and principles apply to things and processes that courts and legislatures have chosen to call "evidence.")