If the poster was the accident investigator, and he based his findings on evidence that he is unable to produce, that would be irresponsible, as it is his responsibility to find or determine the causes of the incident. I don't see how a poster on the internet bringing up a possible theory in a thread full of theories with a few facts sprinkled in could be irresponsible, as he didn't possess a responsibility in the first place, and he made it very clear where and how he saw it.
And this is the internet, in a subtopic almost entirely dedicated to informed speculation. It happens, and sometimes, there isn't even any new evidence, purported or otherwise, to support it.