Your husbands defense is classic DAVO. @Mar
duck posted this link awhile ago that explains it.
What is DARVO?
Jennifer J. Freyd, University of Oregon
DARVO refers to a reaction perpetrators of wrong doing, particularly sexual offenders, may display in response to being held accountable for their behavior. DARVO stands for "Deny, Attack, and Reverse Victim and Offender." The perpetrator or offender may Deny the behavior, Attack the individual doing the confronting, and Reverse the roles of Victim and Offender such that the perpetrator assumes the victim role and turns the true victim -- or the whistle blower -- into an alleged offender. This occurs, for instance, when an actually guilty perpetrator assumes the role of "falsely accused" and attacks the accuser's credibility or even blames the accuser of being the perpetrator of a false accusation.
DARVO as a concept is based on observation and analysis. The author has not yet published systematic empirical research testing the coherence or frequency of DARVO. However, the first empirical research specifically testing the concept of DARVO is completed and the manuscript report is in preparation (Harsey, Zurbriggen, & Freyd, in prep).
Other observers have likely noted the same phenomena and related phenomena using different terms; the author has been informed that some people have found the term DARVO a helpful mnemonic and organizing concept.
Also the presense of DARVO is not necessarily evidence in support of the accusation of guilt; a truly innocent person may deny an accusation, attack the person making the accusation, or claim the victim role. Future research may be able to determine the probability of a DARVO response as a function of guilt or innocence. The author hypothesized that some sorts of denials and reactions such as DARVO are more likely when the perpetrator is guilty than innocent (Freyd, 1997); however this hypothesis has not yet been tested. Furthermore, even if research indicates that a DARVO reaction is more likely when there is actual guilt, it would be an error to use a DARVO reaction as proof of guilt.
For now the concept of DARVO is offered as potentially memorable and useful term for anticipating the behavior of perpetrators when held accountable, and for making sense of responses that may otherwise be confusing (particularly when victim and offender get reversed).*
History of Terminology & Writings about DARVO
Jennifer Freyd introduced the term "DARVO" near the end of a 1997 publication about her primary research focus, "betrayal trauma theory." (For more on betrayal trauma theory, see Definition of Betrayal Trauma Theory
The reference for the 1997 article introducing the term is:
Freyd, J.J. (1997) Violations of power, adaptive blindness, and betrayal trauma theory. Feminism & Psychology, 7, 22-32.
In that paper Freyd explained that DARVO responses may be effective for perpetrators. "...I have observed that actual abusers threaten, bully and make a nightmare for anyone who holds them accountable or asks them to change their abusive behavior. This attack, intended to chill and terrify, typically includes threats of law suits, overt and covert attacks on the whistle-blower's credicility, and so on..... [T]he offender rapidly creates the impression that the abuser is the wronged one, while the victim or concerned observer is the offender. Figure and ground are completely reversed... The offender is on the offense and the person attempting to hold the offender accountable is put on the defense." (Freyd, 1997, p 29-30)
"By denying, attacking and reversing perpetrators into victims, reality gets even more confusing and unspeakable for the real victim. .... These perpetrator reactions increase the need for betrayal blindness. If the victim does speak out and gets this level of attack, she quickly gets the idea that silence is safer." (Veldhuis & Freyd, 1999. p 274).
It didn't happen (an instance) or It rarely happens (a type of event)
It wasn't harmful
Put together they can take the form: "It didn't happen, but if it did, it wasn't that bad" or "It rarely happens, but when it does it isn't harmful." The two claims both serve to deny, but they depend upon different sorts of evidence. They may both be true, but they are sometimes somewhat suspicious when claimed simultaneously (or by the same person at different times), as for instance can occur in response to allegations of rape or child sexual abuse.
Here is the link*What is DARVO?
Hat tip to @marduk