I am Tupac.
By your logic, my overwhelming guilt has caused me to come forward with this information, and it must be 100% true, and that anyone denying my claim is making a fool of themselves by openly admitting it.
In law, the production and presentation of evidence depends first on establishing on whom the burden of proof lies. There are two primary burden-of-proof considerations in law. The first is on whom the burden rests.
In this case, the burden of proof lies on William. However, his only proof is his statement, and if you are to believe his statement, then you must, ethically, take mine as also 100% true.
The second consideration is the degree of certitude proof must reach, depending on both the quantity and quality of evidence.
Quality of evidence: Zero believability, seeing as how anyone on this site can state that anyone else on this site that the first person doesn't like, can make that statement in one of their games, and, with your belief system, should be punished without any physical proof, other then their claims.
The decision maker, often a jury, but sometimes a judge, is required to decide whether the burden of proof has been fulfilled.
Judge, Jury, and neither of them are you, Moja. Twill and his band of crazy-ass-Hunters cannot access PM's, or this would be over. It comes down to whether or not William will come forward with real evidence, other then outlandish claims.
And remember everyone, I am indeed Tupac.