Reusing identifiers after such a short time was a pretty galactic design cockup. I'm a consultant and if I came across that in a design doc or while analyzing a system to form an understanding in my head of how it works, it would have immediately screamed out to me as asking for this kind of trouble. Operator punched the ID in for (civilian) aircraft A, and unknowingly got the trajectory data for (military) aircraft B.

Coding for the 90% common conditions are easy, it's the edge cases where things get hard and true engineering talent shines through. Ignoring them is simply incomplete design.

It's not tolerated in other fields of engineering (eg. civil) and it shouldn't be in ours either.