Hmm. That's dodgy because it also infers that with equal ease, what's said, post death, can be disregarded, even when/if it's the truth, if it fails to suit someone else's purpose.
It is one of the reasons why Historians and legal investigators carefully scrutinize such claims. Are there phone records to prove they talked at a time claimed, did they actually have a relationship that would warrant discussing things of such a nature and all the other things that go into evaluating claims.
Since this claim never made it to court that alone means it is of little value and relevance even if truly alleged by Hawkins.
The unreliability of claims of what people supposedly told them is also why hearsay is indamissible. Admissibility of evidence hinges on reliability and relevance. The former in a general principle of application. The rules of evidence are formed with such in mind. General rules regarding what could be deemed reliable. The latter is actually specific to the case at hand and involves whether the exact issues of the case at hand are impacted by the evidence.
If evidence is of anature generally reliable then it can be considered but tat that point the specifics are evaluated by the trier of fact to evaluate the veracity and what if any impact that has on the actual case. Some things relevant still don't impact the overall decision.
Courts just formally apply rules that are used by historians and others in everyday life. The same exact issues a court looks at regarding reliability and accuracy are used in everyday life just less formalistic application of such.