see;
The Warren Commission Report - 9/11 Commission Report
Of course investigations at a high level with many police and professionals etc can be hijacked, and a replacement story inserted.
Stories like Sirhan Sirhan also come to mind... many situations imo where the perpetrator was guided, set up and 'allowed' to do something. I could list more. I would bet by now if such false flag operations are indeed a reality, their engineers are likely smarter than us, lol
Speculation with too much emotion or confidence is dangerous, but an open-mindedness to anti-status quo scenarios (ie; false flags) I think is perfectly rational for things like this. Trusting whatever story the MSM gives I think is downright naive. I also have some cop-friends who tell you that many times what the public gets/what the media tells us is total shite.
This assumption that the MSM version is the truth unless smoking evidence to the contrary can be produced I think it a bit frustrating. Question the official version = disrespect to the families? etc... its a terrible trap.