I smell a recall coming.

Yeah, probably. I would guess that's more likely a manufacturing defect with that particular shotgun. It's too wrong. Of course, that doesn't excuse Winchester's obviously inadequate quality control.

Wow, was expecting the 'fail' element to be the guy (though in a safety video even then, it would server its purpose well, so not actually a fail), but this....

Wow.

Thank you sir. You might have saved a life. That's ridiculous engineering. Worth more than a simple "recall". God damn....

Don't point your gun at the sky unless you you're willing and able to kill God dead right where He sits on His heavenly throne, young one. He don't give no second chances. But if you do, our hearts and hopes go with you.

What is the world coming to when a man is downvoted for the simple act of advocating the murder of God

That's frightening and a very good PSA.

I thought you couldn't sue gun makers anymore ?

I wonder if there's something you need to remove and/or tighten after shipping that wasn't performed. Kinda like those "remove before installation" pins on older car CD players.

I don't care how bad the music people play with them is. They generally don't kill people.

This is a general rule of gun handling and ownership.
Don't point a gun at anything you do not want to destroy.
I learned about guns in the Boys Scouts from guys who respected and were extremely careful about their firearms.
Anyone screwing around or sloppy was denied privileges.

Years later when I saw how processes protect work environments from mistakes I understood the full logic.

You shouldn't obey it because some guns are faulty. (like in this video)
You should obey it because humans are faulty.

Biggest cause of gun accidents in youth.
Someone thought the safety was on or the gun wasn't loaded...and was wrong.
If you are genuinely curious google "gun safety" or "jeff cooper"

If there was, then it's an even more monumental engineering fail.
As a core principle, mechanisms should "fail safe". So something that needed to be tightened/removed should prevent the gun from firing at all.

http://www.winchesterguns.com/support/files/images/wfa/2015-All/2015-Recall-Info/SXP_Recall-Notice_2.pdf
In deed.

After reading a bit more, it's clear what is going on. This is a striker fire mechanism; the firing pin is not driven by a hammer, but by a spring, in-line with the cartridge. This mechanism is used in many weapons, but it does have a couple possible failure points.

If the spring is missing or is the incorrect tension, the striker may ride forward into the breech where the cartridge is at and when a round is loaded, may cause a slam-fire. This is mostly seen in semi-auto rifles or military ones.

The second failure point, and the one that seems to be the most likely here, is a faulty trigger disconnect. This feature is supposed to disconnect the trigger action from the striker assembly to prevent this exact thing from happening. I would gather that it's not working correctly.

Funny side note, up to 1975 some Winchester pump shotguns were designed this way on purpose. Called Trench or Riot guns, they were intended to be used this way to clear areas of hostiles rapidly by simply holding the trigger down and pumping the action as fast as possible. In fact, the model 1897 Trench gun was so feared by the German soldiers in WW1 that Germany threatened severe punishments to any American soldier captured with a shotgun.

Hear hear! Let us murder God together!! Let me bring my hammer.

Guns don't kill people, gun defects kill people.