TexSigman:
I think he might be able to subtly "draw". Or at least "pre-draw". By this I mean, depending on how things are configured (seating, where the kids' attention seemed to be focused, etc.) Sir W might have just slowly grasped the grip, even if through a jacket or untucked shirt, and wiggled it so that the weapon was loose enough to remove quickly.
My IWB holster is fairly quick to draw from if I'm standing up. But I KNOW, because I've tried, that when I sit the leather flexes enough so the gun's stuck in there. You are right, there's no quick draw from even a properly fitted IWB while sitting.
However, it might have been possible to subtly make it so without being seen, and without actually drawing it. Maybe even pull it out and set it on the seat for maximum readiness, since there was a threat.
I am starting to get in the habit that when I sit while carrying IWB I do this loosening operation as a matter of routine. I'm sitting still, so even if I expose the trigger a little there's no risk. When I get up the gun would probably fall back in place, but I'll never know. I'm developing the habit of giving the grip a little shove through my untucked shirt as I stand up to leave.
I've been reading a lot about how criminals think and how to avoid crime. Pretty much, if you fail to avoid victimhood, like what happened to Sir W, or like in a robbery, and the BG has a gun, you are most likely to find out after it's already pointed at you. By then, it's probably way too late to start cold, draw, aim, and shoot before you're dead.
The key is situation awareness. That doesn't mean just comprehending a developing threat. It means taking steps to avoid/head off that situation as it unfolds.
I can tell you how I would have reacted, and this is NOT to criticize Sir W.
First, no sitting with my back to the door.
Then, sit as close to the door as practical. This also usually avoids being seated next to the stinky restroom.
Then, the minute I hear/see any sign of a ruckus of any kind, THAT is the time to get the gun loose enough to use quickly. That doesn't mean I pull it out or display it. And a mere ruckus or argument isn't quite enough, unless there's something special about it, to yank my 80 year old mother up out of a restaurant and leave without paying.
If it looks like that ruckus might be getting out of hand and my party and me are in a position to do so, I GTFO !!!
But, failing that, if weapons or threats of weapons materialize, I either make the gun very loose in the holster or put it in my lap and click the safety off.
Then, if a weapon gets pointed in my direction, I have a chance.
When I first started taking this approach, it seemed wildly paranoid and awkwardly silly. But now it's really becoming a habit. I will once in a while find myself seated near the door and forget whether I asked or not.