It may not have been actual code. Perhaps only values in a look-up table? Perhaps even values in an area of a multi-dimensional array that was never expected to be used.
The tune-able parameters are lookup tables. I know that Ford, for example, will go through up to 15 iterations per day with testers in the field, in various physical environment, leading up to a release.
The code that detected whether the vehicle was on the road or being tested is what is at issue here. It was a software engineer/manager that implemented it.