There is nothing (in the files available publicly) to gainsay abduction, and evidently nothing in the information available to Mark Rowley (who knows more than we do) to gainsay ABDUCTION.
gainsay
verb formal
deny or contradict (a fact or statement).
"the impact of the railways cannot be gainsaid"
synonyms: deny, dispute, disagree with, argue with, dissent from, contradict, repudiate, declare untrue, challenge, oppose, contest, counter, fly in the face of; More
speak against or oppose (someone)."none could gainsay her"
Well what happens if we put the definition into your sentences:
There is nothing (in the files available publicly) to deny or contradict abduction, and evidently nothing in the information available to Mark Rowley (who knows more than we do) to deny or contradict ABDUCTION.
There is nothing (in the files available publicly) to speak against or oppose abduction, and evidently nothing in the information available to Mark Rowley (who knows more than we do) to speak against or oppose ABDUCTION.
So are you saying it can't be denied and it can't be argued against?