Because we can not evaluate the eye witness, except when they make egregious falsehoods, such as an eclipse during the full moon, a star that hovers over a particular place on the ground, or even a virgin birth.
Then we can reject such testimony out of hand. Certainly a reporter who includes such impossibilities deserves derision, not belief.
This statement shows the extend of your unbelief.
Of COURSE they are 'impossible' - to you.
You seem to require DNA, YouTube videos and stereo, #3D holograms for 'proof'.