I couldn't find the story on it, but there was an instance of a config for some major service getting truncated, but since it was yaml it was more difficult to figure out that that was what happened. I think in AWS, but I can't find the story, so can't really remember.
And fully fair that you can have similar issues in other formats. I think the complaint here was that it was a bit harder, specifically because it did not trip up any of the loading code. With a big lesson learned that configs should probably either go pascal string style, where they have an expected number of items as the first part of the data, or xml style, where they have a closing tag.
Really, it is always amusing to find how many of the annoying parts of XML turned out to be somewhat more well thought out than people want to admit.
Really depends on how the CSV is generated/transferred. If the output of the faulting software is line-buffered then it's quite likely that a failure would terminate the file at a line break.