Yeah, people never lie.*
* Note: I am not saying these guys are lying. There has to be more evidence than word of mouth.
there is more. weldon is lobbing back better than mcenroe . they know it is a long match. think of how far the issue has come in a short period of time. weldon gave a good shot to open the round . he got their attention . he is now counterpunching , their shots have no power , they are tentitive because they think there may be something to this. getting the old guard to admit the charges are possible is a big step.
Was the evidence ever found on Sandy Burglar? No! Was he convicted? Yes! Word of mouth from the librarians worked for that scenario! The chart was probably one of the items Burglar took and it has now been destroyed!
Eyewitness accounts are not "word of mouth". "Word of mouth" that is second hand reports, would be called hearsay evidence, but eyewitness accounts, while often wrong, are admissible in court. The that that we have multiple eyewitnesses is very good corroboration. In intelligence circles we would say the information was confirmed by multiple sources (as long as they either had no direct connection with each other, or each were providing first hand evidence).
What you are asking for, I presume, is *physical evidence". The problem with physical evidence is that it can destroyed, often deliberately.