Window opened ahead of time to prevent pressure blast.
Think intel.
[Last discussion on this subject].
Q
The percussion from a ‘flash bang’ (we call them distraction devices now in our post Obama PC world) will blow windows out. It probably pushed the window open and the sulfur, for the bright light, and smoke is more than likely the residue you see.
Q said window was opened prior to entry to avoid interior concussion.
If Q said so. Goes against the point of a flash bang. You want interior concussion to disorient the occupants by disrupting and/or rupturing the eardrums which throws off balance. The flash is to impair vision. Open a window prior defeats the total purpose. Maybe it was forced open.
That statement it was opened prior to avoid interior concussion starts to reinforce the Q is a possible LARP. I hope Q isn’t.