If such a thing was happening to me, regardless of the application, I wouldn't have let it occur 15 times or more, I'd have done some serious troubleshooting, given Apple a call, asked for help on an internet forum... But hey, if you're a video blogger with a following, a public rant is also an option. Maybe someone from Apple will respond to the negative publicity and fix his problem for him.
They say the definition of insanity is doing the same thing over and over again and expecting to get a different result. Whenever someone says that a piece of software or equipment, "just decided" to do something bad, I lose any faith in their ability to logically troubleshoot the issue they're having. Oh, beware the malevolent, sentient machine!!
To me, it suggests they have no concept of causality and/or have dismissed the possibility that operator error could be a contributing factor.
The fellow is demanding that he be able to Save when he wants, rather than autosave. Hopefully, he means that he can supplementally Save, over and above autosave. The failure to manually Save has likely been responsible for far more data loss than autosave ever has. The Mac is constantly auto-saving - the design goal is to recover from any system crash with minimal or no data loss.
However, if the machine is nearly out of storage, autosave may not work as intended (and manually saving would likely encounter the same problem, since the file size doesn't change based on how you save it). Of course, he ought to be getting out-of-space notifications. We don't know whether that's been happening, but if it has been happening, he wouldn't be the first user I've encountered who couldn't (or wouldn't) correlate an out-of-space warning to subsequent problems.