It seems more likely that it was a freak accident that they blamed on the bugs.

Also, crack pilots who can plot optimal interstellar travel routes seem to completely buy it. Carmen has high math and science scores and pilots ships with FTL capabilities. In order to fling a meteor from Klandathu to Earth, the meteor would have to be propelled using FTL technology. But Carmen’s evidence for the superiority of the human race includes that they developed interstellar travel, so it seems that they don’t believe bugs are capable of it. It’s a point of controversy that bugs even possess rudimentary intelligent.

So it implies that either the federation and the military are far stupider than they appear to be (plausible given their constant incompetence and poor education system), or they are so receptive to propaganda that they ignore the most basic logic (also plausible).