Tell your best work related screw up story!

In the late '80 i was working in a company which sell and installed a car hifi and mobile telephones to the cars...
One monday morning came a lady to the shop and said: " i have a brand new jaguar and i have a time for today for the phone and hifi installion, and i was promised that nobody scratch the jaguar"...
Well, my fellow worker goes to the lady and ask her: "who promised that?"
And everybody start laughing exept the lady...
So she leave the jaguar anyway to us and we start working in it , after that when i was promise the lady that i keep good eye for the jaguar and nothing goes wrong...
She pick the jaguar in a late afternoon and leave the shop.
I was very happy that everything seems to go well...
After 5 minutes she left, my phone rings and the lady was there asking me " i know that the jaguar spends gas a lot but when i leave your shop the tank was full of gas (approx. 21 gallons) and now it's empty..."
I'm like :shock: :shock: what the h*ll happened?
I call a towtruck to tow a jaguar back in and pay a lady a taxi and said that she can rent a car and send a bill to our company, she wasn't happy at all...
We start to check the car and found out that one of the installion guys was put the wireholder clips to the floor and use way too long screws which has hitting the gaslinepipes under the floor...
Prices was very high back then and actually our company loose money in that case, jaguar parts was really expensive...
Now i can laugh about it but back then :cry: