If you check on your results, have a look if they gave you credit for it, if its 0.00, then it doesn't count as being done.
99.99% of the time if you fail a unit credit isn't granted for it, its just as if you didn't do that unit (besides the fail on your transcript).
The whole idea of a course map is pretty bullshit, its just for people who have no idea what they're doing. If you know what you need to do and you know all the rules and requirements enough not to screw yourself over, you're fine. No one will call you up on it.
I've done heaps of dodgy things, like taking a level 1 math subject (which is a requirement for science) in my 3rd year, because its easy and later year results are weighted more heavily for med applications. Most people did it in the 1st year but you technically dont have to.