I'm glad you've never made a mistake.
I've made plenty.
Several years ago, one late morning, the day before a last-minute massive deadline, after a coding binge of over 32 hours, I accidentally deleted a .c file (while cleaning up various debugging logic I didn't need in there anymore) that contained the majority of the work I'd been cranking out. I hadn't done any checkpoint checkins, and had nothing in the way of backups. This was on a linux VM running on my OS X host. I was beyond exhausted, did not have time to recreate everything I'd done over the last day and a half, and even if I did, probably didn't have the mental endurance to do it alll ... over... again... without face planting on my keyboard.
At this point in my career, I'd been a professional software developer for approximately 18 years, and my resume showed a decade and a half string of very demanding projects. There is no one that would've doubted my credentials as a 'pro'. And yet, due to at least a pair of failings on my part, I'd just deleted a ton of work I couldn't afford to delete. If the guy in this video, whose been doing this for 9.5 years, accidentally clobbered his backup, I'm certainly not going to fault him, call him names, or suggest he doesn't know what he's doing. We all screw up from time to time. Well, maybe not you.
As an addendum, after I deleted that file, and after spending some time writing some emergency code that would walk the raw device in an attempt to find the left-over data on there (in Unix at least, deleting a file doesn't really delete the data, it essentially just removes the inode from various inode tables ... effectively rendering it 'gone'. The data is still there, but is free to be overwritten at any point), until I came up with a faster (better?) idea: this was a VM running on my OS X host ... which means there were very large files sitting on my OS X box that represented the 'VM' as a whole. I ran a grep against those files for a string I knew would be in that .c file, and got few hits. Opened one of those massive binary files, found the data, wrote it out to a tmp file and, voila, saved my own ass. Whew! You can guarantee I checked that file in asap.