The false flag delusion is now a universal thing on line whenever a member - or self proclaimed representative - of your own particular tribe does something wicked.
I remember when the Boston marathon bombing happened, or was still fresh in the news, I was in my local barber's. Bloke comes in, clearly a friend/acquaintance of the staff, chatting and gabbing away like mates and he - Asian, but fully western/local with no hint of accent or overt religious leanings - stated with reference to the news on the TV screen that of course the Americans had done this themselves to make Muslims look bad and justify their war on terror.
He wasn't ranting, speculating, guessing or reporting what he'd heard from some secret source..simply calmly stating it as an everybody knows obvious fact, his default interpretation of such news. The fact that the suspects were identified, one arrested, confessed, tried etc simply didn't come into the equation. A Muslim terrorist attack was, could only be, a set up by the CIA.
More bizarrely when Lee Rigby was murdered it was effectively broadcast on live TV, and certainly the perpetrator calmly announcing his justification, blade in hand and walking towards the camera with blood-covered hands. Arrested - on camera - tried, unashamed and unapologetic, convicted. And yet the next day there were links on my facebook to people dissecting the still photos of the videotape arguing the blood on his hands had been photoshopped on and this was an obvious "false flag"/set up and he had been framed...and other people were enthusiastically going along with it!
The assumption the murder of this MP may somehow reflect on the Leave half of the EU referendum is clearly as much in the minds of right-leaning leavers as left-leaning remainers when their first instinct is to cry "set up!"
The internet age churns out more nuts than Brazil.