(1) An examination may be incomplete with the applicant neither passing nor failing.   He may not pass until he has successfully completed each part of the examination separately.   The examination is incomplete, therefore, when it is discontinued for some reason other than the applicant's lack of ability.   For example, when a vehicle has a puncture or otherwise malfunctions during the driving test for reasons not attributable to the driver, the test is discontinued but the driver is not disqualified.