But, thanks to commenter CCostin, I learned that California law takes a different approach as to point 2 above (though it’s the same as to points 1 and 3). California Evidence Code § 913 expressly states,
(a) If in the instant proceeding or on a prior occasion a privilege is or was exercised not to testify with respect to any
matter, or to refuse to disclose or to prevent another from disclosing any matter, neither the presiding officer nor counsel may comment thereon, no presumption shall arise because of the exercise of the privilege, and the trier of fact may not draw any inference therefrom as to the credibility of the witness or as to any matter at issue in the proceeding.(b) The court, at the request of a party who may be adversely affected because an unfavorable inference may be drawn by the jury because a privilege has been exercised, shall instruct the jury that no presumption arises because of the exercise of the privilege and that the jury may not draw any inference therefrom as to the credibility of the witness or as to any matter at issue in the proceeding.
This by its terms applies equally to civil and criminal cases (see People v. Holloway (2004)). And, because the National Abortion Federation’s claims are mostly California law claims, California privilege law wold apply (see Federal Rule of Evidence 501). And that includes rules barring drawing adverse inferences from privilege claims, as the Ninth Circuit specifically held as to a similar Alaska rule in Home Indem. Co. v. Lane Powell Moss & Miller (9th Cir. 1995):
Lane Powell argues that Alaska Rule of Evidence 512, which prohibits negative inferences from a witness’s claim of privilege and which allows the court to instruct the jury not to draw such inferences from claims of privilege, is not a law of privilege because it “has nothing to do with how the privilege is ‘determined.'” Therefore, according to Lane Powell, state rules which do not govern specifically how privileges are determined are outside the scope of Fed.R.Evid. 501 and inapplicable in diversity cases.We believe, however, that Alaska’s law of privilege does include Rule 512 even though Rule 512 does not explicitly address how privileges are determined. Rule 512 is contained in the chapter of the Alaska Rules of Evidence which is specifically entitled “Privileges.” It is part and parcel of Alaska’s entire body of privilege law. Merely because the rule pertains to the drawing of inferences from privileges does not mean Fed.R.Evid. 501’s mandate to apply state privilege law is inapplicable. Fed.R.Evid. 501 “dictates that we look to state law to determine whether a court must allow a jury to draw a negative inference from a party’s invocation of a privilege.”Therefore, we find that the district court properly applied Alaska Rule of Evidence 512 in barring Lane Powell from raising negative inferences before the jury based on Home’s assertion of the attorney-client privilege and in instructing the jury not to draw such inferences.
But here’s a complication (on top of a complication on top of a complication): This only applies to those parts of the lawsuit that are based on California law. Part is based on Maryland law, because some of the surreptitious videorecording took place in Maryland, and Maryland evidence law does allow adverse inferences in civil cases based on a witness’s taking the Fifth (see Windesheim v. Larocca (Md. 2015)). And part is based on federal law; federal law likewise allows such adverse inferences in civil cases, as I noted in my original post.
In such situations, (1) where the evidence relates only to the California claims, the California rule would apply, but (2) where the evidence relates to both the federal and the California law claims, “federal privilege law governs,” see Wilcox v. Arpaio (9th Cir. 2014). (I can’t speak with confidence about what will happen if the evidence relates both to the California claims and Maryland claims.) This means it might be especially important whether the Center can get the federal claims (under the Racketeer Influenced and Corrupt Organization Act) and perhaps the Maryland claims thrown out before trial. If the federal claims (and possibly the Maryland claims) stay in, then the Federation would likely be able to argue that the Center people’s refusal to testify should be counted against the Center (so long as the facts about which the Center people refuse to testify are relevant to the federal or Maryland claims). If the federal and Maryland claims are thrown out, then California evidence law would apply, and no such argument would be allowed.
So the matter is more complex than I first thought, and part of my answer was incorrect, since it relied solely on what the federal Constitution allows, and didn’t take into account California law. Many thanks again to commenter CCostin for opening my eyes to this.
Finally, note that point 3 from my original post remains: A witness who takes the Fifth as to some matters can’t then try to provide testimony on the same subject that’s helpful to the side that the witness might want to support. So if the Center for Medical Progress people take the Fifth as to what they did, they thus likely wouldn’t be able to testify about facts (if there are such facts) that might help them show that certain conversations weren’t private, that the confidentiality agreements they signed might be invalid, or whatever else they want to prove. And if they do testify about certain matters, their testifying would waive their Fifth Amendment privilege, at least as to those matters. So even if the Federation can’t argue that the refusal to testify is itself evidence against the Center, it can argue that the Center just hasn’t introduced enough evidence to rebut the Federation’s evidence.