There's another video out there of an M1 Garand self disassembling in a woman's hands due to the same issue; a squib load leaving a bullet in the bore, followed by a full power load. It was essentially the "tap-rack-bang" exercise, which is taught in self defense and competition pistol shooting ("that round didn't work, so let's try another one as fast as possible"), so be careful how you practice what you're taught. Better yet, be taught how to recognize and respond to a squib verses a misfire. There in this video we see the importance of the difference.
Anytime you get a cap detonation without a main charge ignition, or a different sound or feel, it's probably a good idea to stop, "take inventory", and check things out.
I used "bore rider" bullets in my Win 30-30 for a long time, but they always fit tight in the bore upon chambering, being about a thousandth larger than they should be for that bore. So what, I thought, I'll just force the lever home with a little more pressure when chambering.
It worked fine for a long time, that is, until I decided to take a break one day, and so I emptied the chamber to let the gun cool. I'd done this a hundred times, but this time, unbeknownst to me, that one time, the bullet stayed behind as the case was extracted. I didn't notice the powder spilled all over inside the gun because it was in bright sun and I was wearing prescription sun glasses which favor long distance sight at the expense of close up sight. And anyway who looks for that sort of thing? So when I went to shoot some more, the next round was a bit harder than usual to chamber. Oh well, so I have the rifle up in the firing position, hammer back, safety off, finger on the trigger, lining up the shot and ready to fire. But, I think, maybe I should check out that issue of the fresh round being a bit harder to chamber.
That's when I discovered that I had the fresh round with its bullet right up against another bullet in the bore. These were 170 grain cast, and the powder was a full load of Win 748 producing nearly 2,000 fps from a carbine. I'm pretty sure that could have killed me right there if I'd pulled that trigger. It would have bad in any case. The Win '94 bolt lock design isn't all that robust compared to more modern designs.