Is a scientist disingenous when he theorizes that multiple universes are a possibility, because we can't know for sure if they exist or not? I think not. There are those who do not want to believe in evolution, however you define it. They will never listen to anything that you say because they find the idea offensive and God dishonoring. Then there are those who do not want to believe in God no matter what, however you describe Him/Her/Them. They will never listen because they believe that the idea of God is insulting to their intelligence and disagrees with science.
Both groups have a bias, a filter that all information must pass through. Very few can look outside of themselves and past an " either this or that " belief. For example some like to speak of " junk DNA ". If 10 years down the road you understand what it was really for then it is not junk. It remindds me off my Dad working on anything. There were always left over parts. Since he didn't know what they were for, logically they were junk.
Just because science does not currently have the knowledge to fully understand everything about DNA, does not make some of it junk. It would not make me disingenous to say that it could be useful after all because science doesn't know everything, and so cannot prove it's junk. I am also not disingenous for believing in life being seeded on this planet by an intelligence that we cannot currently understand with our present technology.
The problem is dogma on both sides. Science versus God. God versus Science. I won't discount science because of man-made religions. Neither will I discount the existence of a creator because of limited human technology.