"Both Boeing Co. and Airbus Group NV, the world’s largest makers of commercial airplanes, have issued statements questioning Roberts’s claims."

Note that they didn't actually deny it completely. To me, this says they either don't want to say "it's impossible" for fear of liability, or that they know there are some holes and don't want to talk about it.

Also, comparing what the two companies said is interesting: I prefer Boeing's rather direct "they are isolated" response and find it far more reassuring in comparison to Airbus' wordy and vague statement.