I left work before I realized I left out the part about truth being Ms. Allen's burden because it is her defense to defamation. (In US law, once the plaintiff has made a prima facie showing of their case, the burden shifts back to the defendant to prove their defense.)
Common elements of defamation in US law:
1) a false statement purporting to be fact concerning another person or entity;
2) publication or communication of that statement to a third person;
3) fault on the part of the person making the statement amounting to intent or at least negligence; and
4) some harm caused to the person or entity who is the subject of the statement.
Mr. Arrington has made a prima facie showing of the elements of defamation. (This doesn't mean that he's proven his case, since that is a factual determination by a judge or jury. It simply means that he appears to have shown sufficient evidence of each element that the factfinder could find for him.) I leave it to you to read the massive of wall of text to see how each element is met.
Truth is a defense to defamation, under American law. Thus, it is now Ms. Allen's job to prove the truth of the allegedly defamatory statements. In this regard, the photo is a significant obstacle to overcome in showing the truth of her statements, if, as suggested, she was several hundred miles away from the plaintiff at the time of the alleged incident.
Correct that truth is a defense. But, as I understand it, the defendant does not at any point have a burden of proof in a civil case, even if the plaintiff has made a prima facie case. That's just not how burden of proof works for any tort under US law. The burden is essentially always the plaintiff's by a preponderance of the evidence. Many defendants try to prove truth of their claims so that the plaintiff cannot meet their burden of proof to show falsity. But that doesn't mean they have the burden of proof, in the sense in which it's typically used.
Yes, you're missing a crucial distinction: there are different types of defamation. Defamation of a public figure (which the linked law journal article you provided discusses) places a higher burden on the plaintiff than defamation of a private individual. A public figure must demonstrate the falsity of statements made against him, and must demonstrate malice. The justification is that a public figure is more readily able to defend himself or has others willing to defend him in the court of public opinion.
For defamation of a private individual, the burden of truth remains with the defendant (once the plaintiff establishes a prima facie case). See, e.g., Ellenberger v. Espinosa (1994) 30 Cal.App.4th 943, 953. There are slight variations from state to state, but this is the general rule. (By the way, in case you are wondering, in the legal field, citing a case or statute trumps a law review article or Wikipedia every time.)
As far as I can tell, it doesn't say what you claim it does. There is no mention of burden of proof or prima facile case at all. It merely states that truth is an absolute defense, but that is only the case because it precludes the plaintiff meeting their burden of proof to show falsity.
Since you mention a distinction between private and public indviduals, I suspect you are confusing the issue of burden of proof with the "actual malice" standard, which must be met to establish defamation of a public figure but not a private figure. This is established by Supreme Court precedents Arthur v Sullivan and Getz v Robert Welch Inc, both of which are cited in the law review article I mentioned and both of which maintain falsity as a required element of the offense. (In case you were wondering, Supreme Court precedent trumps Circuit Court precedent in the US, so even if the case said what you claimed it would not be informative about the state of the law of defamation.)
Common elements of defamation in US law: 1) a false statement purporting to be fact concerning another person or entity; 2) publication or communication of that statement to a third person; 3) fault on the part of the person making the statement amounting to intent or at least negligence; and 4) some harm caused to the person or entity who is the subject of the statement.
Mr. Arrington has made a prima facie showing of the elements of defamation. (This doesn't mean that he's proven his case, since that is a factual determination by a judge or jury. It simply means that he appears to have shown sufficient evidence of each element that the factfinder could find for him.) I leave it to you to read the massive of wall of text to see how each element is met.
Truth is a defense to defamation, under American law. Thus, it is now Ms. Allen's job to prove the truth of the allegedly defamatory statements. In this regard, the photo is a significant obstacle to overcome in showing the truth of her statements, if, as suggested, she was several hundred miles away from the plaintiff at the time of the alleged incident.