My thought is the DPS did not design the course of fire to actually test your shooting abilities. The test is far too easy for that. They only want you to demonstrate that you can follow instructions and safely operate your firearm.
I have taught new shooters, experienced shooters, handicapped shooters, and I have never had anyone fail the shooting test. They haven't all passed the first time, but they all somehow passed before the 3rd time. And when it's all done - that's all that matters.

Of course, these are my own personal opinions. Your mileage may vary.