In the engineering world Murphy's Law states that if there is a 1 in 10 billion billion chance of something being fitted the wrong way, upside down, inside out etc. someone, someday, will manage to do it.
Sod's Law says that out of 10,000 engineers I will be the one selected to sort out the mess.
The best Murphy's Law story is an apocryphal one dating back to the war. A particular Lancaster was know to fly like the proverbial brick outhouse.
A succession of pilots, some very experienced and senior, complained about it but the engineers could find nothing wrong, until a major strip down inspection.
It was then found that the elevator, the bit that makes it go up and down, had been fitted upside down, a feat hitherto thought impossible.