That's not careless, that is either getting too comfortable or working too tired. Been there too many times.
You got that right. Me and a certain neon sign transformer have been friends for too long, I used it as a laser power supply in the 80s & 90s, it used me as conduit to ground on every chance it got! #$#&*#%@!!! Neon Sign PSU!they say you do not get electrocuted when you are new.
they say you get electrocuted when you get comfortable with electricity.
And that's not to mention the TVs and CRT (including a few macs) that got me as well!
After a while, you just get used to it!