Have you ever failed to capture a shiny ?

Not in US/UM, no. I've never failed a shiny in these games, considering how easy most of the Ultra Worm Hole shinies are to catch.

i dont think there has been a moment that came to mind. the closest is soft-resetting because of getting a shiny of the wrong nature, but i already caught said shiny, so that doesn't really count. i generally take great precautions to avoid being in a situation where i would fail to catch a shiny. x.x

Yes, once in X with an absol and then again doing my first SOS chain in sun, I was obviously not properly prepared and I killed a Beldum which is my absolute favorite shiny mon.... Luckily I came back with more knowledge and resources and caught one

I technically have two, but neither were my fault.

In Black 2, your first time through Castelia Sewers, you travel with your rival and have to go through double battles. You can already see where this is going... we ran across two Zubats- the difference is that one of them was a different color! I guess my Rival didn’t like that, because he decided to go straight for it.

Next, in X, the catching tutorial. Now, we all know about the Poochyena in RSE and other Pokemon used just as an excuse to choose a starter or teach the player how to catch Pokemon. Now, with all the shiny locked Pokemon in X and Y, you’d think they would’ve thought to lock this one as well. But... no. Serena came across a shiny Bunnelby. She didn’t seem phased that it was a different color... she was more concerned about teaching me how to do something I’ve done in many games before.

But as for shinies that I actually messed up, I’m lucky that day hasn’t come, but I also wouldn’t be surprised if it did because I’m pretty scatterbrained