IANAL, and I am assuming you are a lawyer - I interpreted @NoMoreNicksLeft as saying that it's a judge's responsibility to determine whether or not evidence is admissible - before it gets to a jury. And that's also what the article is talking about - "The examples should illustrate circumstances that may satisfy the authentication requirement while still leaving judges discretion to exclude an item of evidence if there is other proof that it is a fake. "
Judges have a role in excluding evidence which is more prejudicial than probative. In the case of a fake voice recording, hearing someone who sounds like the accused participating in a crime may prejudice the jury even if they later hear evidence that the recording is fake. (This is probably even more true for faked videos.)
