Have you ever had an instance of you only noticing a rip's error after it was uploaded?
Absolutely, so many times.
For the sake of not making other people feel bad, I'll focus this answer entirely on my own mistakes. And these mistakes are most often noticeable with visual rips, which I have a lot of.
The First Law of Video Editing
No matter how carefully you edit, there will always be at least one mistake you only notice after the video's published.
Here's a major example: "The SiIvaGunner 7th Anniversary Art Gallery"
I edited together this video. As you can see in the description, there are three corrections listed, because while I went through many drafts, I didn't completely watch the final draft all the way through. Big mistake.
The background music fades went out of sync twice, overlapping with video submissions, and Sinci1 was credited incorrectly. I felt pretty bad about it, but I felt better that we were able to add corrections.
I edited 2024's gallery too, and tried to avoid mistakes as much as possible, doing so many once-overs and getting more eyes on it. I'm sure there's at least one mistake somewhere in there though, but at least the audio was fine.
Sometimes you can pass off mistakes as intentional jokes:
"Smurf Cat but it's Skibidi Toilet but it's a dance party with your favorite characters #shorts", which is a video on the SiIvaGunner channel, has the Numberphile's head visibly show up behind SpongeBob's leg even though he's supposed to be in front of him in the room. That was a mistake, but maybe it works because he's not supposed to be in the "original" video.
And for a throwback, an example of an obvious mistake I made (9:54) on a video before I ever contributed to SiIva:
The art for that shot was already made! I just forgot to put it in before rendering, and didn't watch the very final version (again, always watch your final versions all the way through, even if you're tired of it.) We passed it off as a gag, but I had to make sure to never do that again lol.
In terms of audio in rips, a recent example is this rip: Forest Moon Lake - Ganbare Goemon Kirakira Dōchū: Boku ga Dancer ni Natta Wake
Really subtle mistake, but at 0:46, both string layers are in the same right-panned channel, instead of one being in the left and the other being in the right like they're supposed to be the whole time.
I have several other musical examples from my own rips, but I don't know if I want to send them because I feel like it might damage the listening experience, hahah… it already has for me, on a few of them, but I try my best to ignore it.
Often times the mistakes are pretty subtle though, or technically not mistakes but things I wish I had done, or had planned to do but forgot about.
For example, in Ruby Illusions - Final Boss (In-Game Version) (Beta Mix) - Sonic Mania, I had an pink-tinted fog overlay over the video (meant to represent Fools' Spirit), but while editing it I turned it off to be able to see the stuff behind it better, and I forgot to turn it back on when I finished.
To be fair, I was crunching the fuck out of that video… I had a real life adventure on the way to get that video made, but that's a story for another time.
Mistakes happen all the time, and everyone does it, very much including me. Just don't beat yourself up over it, like I have. I'm learning to let it go, like water off a duck's back.