Ok, I never noticed that. I just read the captions and assumed obvious misspellings were auto-generated.
For example in this video[1], the caption text is "L1D cache misses" but he's actually saying "L1-dcache misses". (The Linux terminal screen he's showing does display "L1-dcache".) Even though that video is not labeled as "auto-generated", I assumed it was because of the bad caption. Based on your info, I guess CppCon uses humans like Mechanical Turk or other non-domain typists to manually add the captions.
In college, I met a deaf guy who always had two women accompany him to lectures; one of them would repeat everything into a mouth-covering microphone to generate an automatic transcription and the other went over it to correct obvious errors. They generated a lot of nonsense, especially when the German professor was using some English loanwords for CS concepts. I was always amazed that the deaf guy still somehow managed to learn something from these garbled transcriptions.
[0] https://www.youtube.com/watch?v=om6HcUUa8DI