Earlier quoted context omitted.
Excluding fake evidence is very much a responsibility of the judge. In the age of Fox News, letting the jury decide for themselves whether or not made-up bullshit is actual evidence seems like a recipe for disaster, and not necessarily one that errs on the side of caution.
To the contrary, in US courts the jury determines whether evidence (documentary, testimonial) is credible or not, and what weight (if any) to assign it. (Experts, à la Daubert etc., are a different matter because they give expert opinions, not factual evidence based on personal witnessing of the events in the case, so the judge does perform a gatekeeping function, essentially to ensure the underlying field/science is…
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. "