The conspiracy theory fails on the most basic principle of the scientific method. Burden of Proof. They speculate as to what can be done, badly, but they never provide any evidence to show that it did in fact happen. They therefore cannot defensibly assert what they are asserting. All they are doing is speculating.

Of course, we must be careful. While it is true that the truth will in theory be consistent. In practicality, it is impossible for every facet of the historical record to be perfectly consistent. There will always be some minor discrepancies here and there.