This helps a little. Thanks. So say there's a recording of a jailhouse conversation. And the prosecution is saying the D said the car was green. And the defense is saying the D is heard saying the car was gray. NOW does BER apply?
Beluga explained why BER doesn't apply here, but I thought of another way to phrase things that might help. BER applies when a recording/document is literally the best conceivable evidence, not just the best available evidence. So what's the best conceivable evidence of whether or not a recording contains a conversation about a green car? The recording itself. Nothing could possibly be more on point. What is going to be the best conceivable evidence about the actual greenness of the car referred to on the audiotape? Not the audiotape, I guess that would be the car itself.