canada, with some comparative contrast with the united-states
Cherry-picking draws no special analysis in defamation law.
Terminology
First, whether a statement is defamatory is separate from whether it is true or false. In Canada, for example, a statement is defamatory as long as it "would tend to lower the plaintiff’s reputation in the eyes of a reasonable person" (Grant v. Torstar Corp., 2009 SCC 61). And in the United States, courts also separate the two. See for example, Pegasus v. Reno Newspapers, Inc., 118 Nev. 706 (Nev. 2003)
The general elements of a defamation claim require a plaintiff to prove: "(1) a false and defamatory statement...
However, ultimate liability for defamation does depend on the truth or falsity of the defamatory meaning. In the U.S., the plaintiff must generally prove the defamatory meaning is also false in order to make out the case. In Canada, the burden shifts to the defendant to prove on a balance of probabilities that the defamatory meaning is true in order to avoid liability.
Whether the meaning conveyed by a cherry-picked statement is defamatory
The impugned statement may convey more than its literal meaning.
Courts recognize that meaning is contextual. The defamatory sting of a cherry-picked statement may come from some non-literal meaning.
In Canada, (see Weaver v. Corcoran, 2017 BCCA 160, at para. 71):
Words may convey a defamatory meaning literally, inferentially or by legal innuendo. Literal meaning is conveyed directly; inferential meaning, indirectly; and legal innuendo, by extension based on extrinsic facts. ...
Where the literal meaning of words is in issue, it is unnecessary to go beyond the words themselves to prove that they are defamatory. Where a claim is based on the inferential meaning of words, the question is one of impression: what would the ordinary person infer from the words in the context in which they were used? Both literal and inferential defamatory meaning reside within the words, as part of their natural and ordinary meaning. In contrast, where legal innuendo is pleaded the impugned words take on defamatory meaning from outside circumstances beyond general knowledge, but known to the recipient.
Truth or falsity of the defamatory meaning
It is the defamatory meaning determined through the above analysis that would also have to be shown to be false (in the U.S.) or for which truth of that meaning would be a defence (in Canada).
Said another way, if the use of the cherry-picked statement conveys some defamatory meaning X, the plaintiff in the U.S. has to show X is false (the defendant in Canada would have to show X is true).
Therefore, it seems impossible for a successful defamation claim to flow from defamatory meaning that is merely the literal fact that the words were said, since that will always be true.
If there is a defamation claim from a cherry-picked statement, it would have to be because it communicates something else, that something else being defamatory, and that something else being false.