Storytime: Once upon a time, I was a young grasshopper at a small consulting firm at which every employee was issued a Windows machine, our source control system was "\Customers" on C: drive, and our deployment strategy was "putty + copy-paste + hot-reload".
One morning, I heard something terrible while my boss's boss's machine was booting. Something akin to grinding. The thing was angry.
I gave boss^2 a heads-up that his hard drive might be failing, and that he might want to run a S.M.A.R.T. check on the poor thing. I also asked where the backup hard drives were, because I was brand-new and assumed that I just hadn't been issued one yet.
I checked the supply closet, found no hard drives, popped over to the office admin person, and recommended a deal I'd seen on some WD black drives before I realized that the place had gone quiet.
Everyone looked at me like I was from Mars.
Exactly 7 days later, boss^2's hard drive failed. We lost a week of work and had to zero out a 5 days x 3 employees worth of billable hours. We also ended up delivering late.
The client was pissed.
Based on the nasty looks that I got afterwards, it appeared that the standard assumption was that I had tampered with the drive to prove a point. (Um, nope).
I have since learned to ask prospective employers about their backup strategy.
Nasty looks seems to be the sign of them realizing how you proved them to be incompetent.
Incompetence will cost them their job.
If I had fuck you money I'd just call them incompetent fucks and laugh at them.