Am I missing something or would they have also failed them if they had been driving a car with a manual transmission and made some limited use of engine braking to slow the vehicle instead of immediately depressing the brake? Seems to me that the provided reasoning also implies that downshifting to a gear other than neutral would result in failure...

The problem (as usual) with non outcome based testing is that the process is more important than the result.

I am pretty sure it would not have. The comments about "come back without an electric car" pretty much tells you what was going on.