I normally do my own, as well... company car, not allowed to touch it. I couldn't even change a fuse without risking my job.
So, I followed the rules, and took it to the professionals. I didn't check it when I left, because I wasn't allowed to. Got back to the shop, and the transmission quit working, and the engine was smoking like crazy (was smoking for about 20 mins before that, but I never stopped, cuz I'm a "good employee".)
The lead technician at the company (yep, they have technicians, but outsource oil changes..
), through brilliant deduction, determined that they'd actually drained the trans pan, thinking it was the oil pan, and then added 5.5 more qts to the crankcase. Talk about a gutless econo-van...
Anyway, point was (mine) that there is a chance that oil can hydrolock the engine. It's a rare chance, but the above kind of thing happens more times than you'd really believe.