to not having the crankcase drain plug reinstalled. Yes, and the little red light preceded the engine welding itself into junk by about 30 seconds.
Can you say " OH SHIT !!!!!!"
That reminds me of the time i had changed the oil in my 70's something VW rabbit , i hadden't tightented the drain plug tight enough , and as i took the car on a post oil change run , the drain plug came loose , i heard a clunk and saw a cloud of smoke , i watched the oil pressure plunge , i was on the interstate at 70+, i put the car in nutral ( it was a stick shift ) , turned off the engine , and coasted to a PEPBOYS . Luckly they had a drain plug for my car , I replaced this and filled it with oil , i crossed my fingers and started the car , i got 50k+ miles from it untill i had to get the heads re-built . YES I WAS A LUCKY MO-FO !!!!!!!