My biggest ever professional mistake. See I was a factory worker and working nights. That night one thing I had to do was put our product into a fancy oven. It would run for over 12 hours but at x temperature for a few hours, then y temperature for some more hours then z temperature for some more hours etc. I took about $90k worth of product(internal cost, not sell price) put them in the oven, went to the touchpanel pressed a button, did all the paperwork, and went home.
Day shift started at 6am, by 630 I got a phone call from the manager asking what the hell happened last night? I said nothing, everything went smoothly. He said well the oven is over 2x the max allowed temperature for the devices. See on the touch panel there was a button for "auto" that started the pre-programmed temperature cycle the button immediately below that just turned the heat on full blast untill manually turned off, no confirmation, no protection at all. I cost the company over twice my annual salary by pressing the wrong button on a touchpad.
Basically it was determined that it wasn't my fault and was poorly designed. The touch panel got redesigned and shortly afterwards anything besides auto required entering a password. I wasn't punished at all but probably took a few years off my life in anxiety and fear.
My favorite is I ordered dog food. It was scheduled for 2 weeks (with prime). It arrived next day. Amazon still said it wasn't shipped yet. To this day "expected delivery date is currently unknown" in the Amazon app. I ordered it in May. It does give me the option to request refund but I haven't done it as the food was actually delivered and this seems like some employee forgot to scan the sticker at some point.