The story starts to make more sense if you consider the possibility that one of the perpetrators/witnesses in the attack was a Canadian intelligence agent or a Muslim informant who was conducting surveillance in the mosque and either went rogue or whose role can’t be identified in the investigation.
And did they search the basement of the mosque? What’d they find? MANPADS?
Khadir was (apparently) questioned for 12 hours after the attack - not normal behaviour for a witness.
One theory is that he and Bissonet really did attack the place together (for whatever reason).
The Canadian Govt realised that the optics of a Muslim on Muslim attack just one day after Trudeau declared for refugees were awful, so (the theory goes) offered the mother of plea deals to Khadir to remove him from the suspect list, and so allow Trudeau to use the narrative of a lone, white gunman.
IF there’s anything in that theory then there would be discrepancies in the camera & ballistic evidence that would come out in trial. If there is a trial.
If this IS a cover-up then I would hope that a disgusted policeman or forensic functionary would leak the truth.