Thats not very fair though is it. Some people can get really nervous on their test day and end up making silly mistakes, but that doesnt mean that their driving is sub-standard or that they are a dangerous driver!
I failed my first test because of a major fault, my driving had been perfect up until then and I was actually on my way back to the test centre, my examiner wasnt very clear about where he wanted me to go so I went the wrong way, and he ended up slamming his foot on the brake, even though there were no cars about whatsoever and there wasnt a risk of me hitting anyone or causing a collision.