I don't recognize the brand pistol in the video. My first hunch was Colt but not sure.
A couple of things stand out. First a little history. I have a Colt Trooper .22LR. For the longest time, it was dead nuts accurate. All of the sudden, it is spewing bullets all over the target. Something is wrong with it. On examination, the cylinder is not locking up reliably. With the hammer back, I was able to rotate the cylinder a 1/16" until it locked. I put the revolver away and added the repair to my to-do list.
That was a good 15 years ago. Racer88 comes along with his Python adventures which was the poke I needed to get on the Trooper. It's not a Python but any Colt port in a storm will do. I research the shit out things. Some things I came across. Colts don't like to be operated slowly or gingerly. D/A, pull that trigger like you mean it. S/A, cock that hammer same way. As it is designed, the cylinder needs some inertia to finish the rotation and lock into place. There is a small gap in the works, at the end of the rotation, where nothing is touching the cylinder to positively complete the rotation. Inertia is the key ingredient for full rotation. Second, any drag on the cylinder will kill the inertia and it won't lock. The Trooper is a simpler system than the Python family so I don't know if this applies to the fancy pants Colts.
In this video, it appears that the guy pulled the hammer back slowly. While looking away, his left hand seemed to interfere with the cylinder rotation. It is entirely possible for the cylinder to be out of alignment. Squib load or firing another round on top of a stuck bullet seems to happen a lot in Cowboy Action shooting if you believe the internet. There are a lot of shooters that reload. For whatever reason, they often load to the absolute minimum to get the bullet out of the barrel and no more. Sometimes it doesn't work out. The point is, don't dismiss a squib as a possibility. I've only had to knock one bullet out in my whole life but it happened.
Back to the Trooper. I do remember operating this revolver gently and with care. When I got to it recently, armed with the knowledge that these need to be operated with purpose, it seemed to lock up just fine. I stripped the whole thing down and found no broken or worn parts. While apart, it got a good cleaning and fresh lubrication. It is as slick as ever now. Sidebar, it was shocking clean inside, I'm used to 22LR guns being filthy from end to end. I can induce a "no lockup" by pulling the hammer back slowly or by putting slight drag on the cylinder during rotation.
You don't have to be abusive for proper Colt operation. Work it with purpose, don't baby it.