Mike, that is priceless!!!
It's the equivalent of some punk holding a gun sideways.
Actually, its quite a bit worse. Holding a gun sideways, while stupid, doesn't risk damage to the mechanism.
Others have explained why it is a bad idea mechanically. Among knowledgeable shooters, its a bad idea socially, as well. Flicking a revolver open or shut publicly displays the fact that you are either ignorant, or arrogant, and maybe both.
You can fix ignorant.
It's dramatic. IT looks good in the movies. At one time it was called "Bogarting", because Humphrey Bogart did it often in the movies. Flip a DA revolver open, to "check it was loaded", then flip, or slap it closed.
Nice, dramatic visual. Directors like that. And besides, it wasn't Bogey's personal gun, it was a prop gun. (apparently "Bogarting" now means something different, and not relative to this discussion
)
Another movie/TV move is flipping shut a double barrel shotgun. Very dramatic. Good for director, BAD for shotgun. (please, don't do this at home, kids...)
A lot of people discover an interest in guns, but don't have anyone to teach them the proper do's and don't. They imitate what they see on the screen (big or small) thinking its what one does. If they're lucky, they just look foolish, to those who know better. IF they're not lucky, they're still just as foolish, but also have repair bills to pay.
its your gun, its your choice, abuse it if you want, and pay the costs out of your pocket. If you to it with mine, I would have a ...difficult time..being as refined, considerate, and gentle as MR Irwin...