I believe that precedent was set with Arvin in F2. He got pole lap deleted because it was red, Dino and Montoya slightly before it and kept theirs. Bearman didn't see it, but if it was a red flag, I guess it was the rules, even if Ollie didn't see it. Tricky subject and I hope for better clarification in the future.
But with the argument FIA have given. They did the red flag at 17.6 seconds over 16:32. (So, at 16:32:17.6 local time)
They then say "Bearman crossed the line at 20.9 seconds over 16:32". So Bearman crossed the line 3.3 seconds after FIA set the Red Flag.
The FIA also states that when Bearman crossed the line it was "with the abort signal/ red flag showing at the start gantry". Which is something we know from footage is wrong.
It takes between 2 and 3 seconds after Bearman cross the line before the red light shows at the start gantry. So let's give FIA the best possible timing on that, and 2sec flat.
That means it takes over 5 seconds, 5.3 seconds, from "Red Flag" to it actually showing. That is a long time.
That also means that Dino Beganovic, who got a red light somewhere between 3 and 4 seconds after setting his time in the F2 qual. Should've lost that time and thus his pole position.
Because, the time from setting the red flag to when it shows cannot possibly be random??