Defendant pays witness to say “I don't remember”. What can be done to
prevent/deal with this?
Will it help if:
Before Matt "forgot" everything, he told what he saw to other people,
and they are happy to testify that?
That constitutes hearsay evidence, which needs to satisfy certain conditions in order to be admissible in New Zealand.
Unfortunately, there is no way to preclude a witness's malingering of "amnesia" or to prevent that witness from blatantly lying under oath. Instead, one has to focus on
(1) other evidence that renders the "amnesic" witness not credible, and
(2) the witness's material inconsistencies in his or her own testimony.
Unearthing a witness's inconsistencies is a matter of knowing what follow-up questions to make (depending on the witness's answers). Ultimately, no crooked lawyer is able to train his client to perjure on any and all follow-up questions that may arise.
In what follows, I will highlight some instances (based on my experience as plaintiff in pro per) of how to deal with a witness's deliberate departures from the truth. Although these matters are litigated in the U.S., much of this is applicable to other jurisdictions.
Bear with me, as I intend to strike a balance between brevity and usefulness so that other pro se litigants get some idea on how to (cross-)examine a witness and/or deal with testimony inconsistencies. For more detail on these issues (briefs, transcripts, and my narrative in videos), see here, here, here, here, and my Youtube channel.
By way of background, in 2015 my father's 2nd wife began harassing the University of Michigan, for which I was working as a consultant. At that time, the University already was in the process of hiring me for full-time employment. Due to her acts of harassment, I asked the court to issue a Personal Protection Order (PPO) against my father's 2nd wife. The court granted it. Few hours after the police delivered the order to her, my former employer contacted the University to make false and defamatory statements about me. The timing and other circumstantial evidence suggests that the employer's acts of defamation are traceable to the service of that PPO upon my father's 2nd wife. Eventually I sued both individuals for defamation and for other wrongs. My former employer and three employees of the University were required to testify at deposition.
One University employee denied --under oath-- that my hire process was suspended because of the defendant's (that is, my father's 2nd wife) acts of harassment. I disproved the witness's testimony by showing records which reflect that the University in fact suspended my hire process because various managers of the University were alarmed by the escalation of the defendant's acts.
The HR Administrator of the University repeatedly malingered amnesia during her deposition. Her lack of memory is not credible, though, since she was centrally involved in the University's deliberations & emails on how to proceed regarding the defendant's acts of harassment.
My former employer (that is, the defendant to my other lawsuit) was the most "amnesic" of all witnesses. Although all three employees of the University gave a strikingly similar testimony [under oath] as to what accusations my former employer made about me, he pretended he was unable to remember the matter. Clearly, a malingering defendant is less credible than the sworn testimony of three non-parties (except where the judicial system is run by corrupt judges).
My former employer brought a witness before whom to notify me of my termination. I think he did that to impress on the University a connotation of alarm, so as to reinforce the scandalous and alarming language he used days earlier. At deposition, he testified that he "does not know why" the witness came with him. After few follow-up questions, he had to admit that he in fact requested his witness to accompany him to his act of terminating me.
Lastly, another way to "corner" a witness's subsequent testimony consists of asking him/her to produce an affidavit early on --or prior to-- the judicial proceedings. This is not always possible, though. For instance, had my supervisors at the University had the integrity to promptly inform me about the calumnies the employer was uttering about me, I would have secured from him some notarized document (when he terminated me) with which to confront his subsequent "amnesia" at deposition.