My source (the prof) was one of the people who worked on the system, so while it might be a tall tale, it doesn't qualify as urban legend. It was being passed on as a "this is what I saw" not "this is what some other guy saw".
Basically, the point was that the guys in charge of calculating weight (for fuel, etc.) literally had no concept of a system component that had no weight. So they're acting like "I don't care how insignificant you think it is, I've got to know exactly!" -- thinking that the software developers were just being stubborn.
Wow. Just wow.
But how could any space-program ME be so inane? How was he smart enough to find the shop every morning if he couldn’t reason any better than that? Would you trust a guy like that to engineer a spacecraft?