I guess it's hard to tell without over-parsing his words, but you bring up an important distinction. It may be fair to read it as a scientist essentially sayin

I guess it's hard to tell without over-parsing his words, but you bring up an important distinction. It may be fair to read it as a scientist essentially saying "we have no evidence it's possible." But as I read it, the addition of "ever" came across as saying he thought it was an unsolvable problem rather than one that had yet to come upon a solution.