Company X and Company Y have each been building a rocket ship able to travel to Mars. After five years of design and construction, the rocket ships have been unveiled to the public, which instantly notices the rocket ships are so similar in design as to be indistinguishable. Ttherefore, one of the companies must have had information pertaining to the design of the other rocket ship.
The statement 'There is only one possible design given the current materials that confers the aerodynamic requirements to reach Mars' would most call into question the validity of the argument.