If eyewitness testimony can be held to never be credible, then that calls into question whether there can be anything but illusion. I'm sure that you will protest that you do not hold an opinion to that extreme. Yet your statement above indicates that you propose, indeed, to hold me to nothing less than that extreme an opinion. As I observed earlier, exaggerate and deny, deny, deny.
You seem to find it reasonable to say that someone has declared eyewitness testimony to not be credible if they say they've seen things the know weren't there.
Anyone who's ever been to a magic show can probably make that statement.