[shubi]

Sorry, but evidence is evidence.

Just so you will understand the term:

Main Entry: 1ev£i£dence
Pronunciation: ‚e-v„-d„n(t)s, -v„-ƒden(t)s
Function: noun
Date: 14th century


1 a : an outward sign : indicationb : something that furnishes proof : testimony; specifically : something legally submitted to a tribunal to ascertain the truth of a matter
2 : one who bears witness; especially : one who voluntarily confesses a crime and testifies for the prosecution against his accomplices
-in evidence1 : to be seen : conspicuous ²trim lawns T areeverywhere in evidence—

[muir_redwoods]

so for your purposes, the ravings of a lunatic, the mumbled dreams of a 3 year-old and the testimony of a drunk are evidence simply because they said the words. Fine. There now can be evidence for anything so where are you, logically?