If the facts are 100% as stated then the examiner did not do the same as most of the examiners I've met would have done.
I was sat in the back of the car during a test and the candidate was following road signs for a location. He missed the small fingerpost sign, that the examiner had mentioned would be there opposite the junction, so the examiner intervened and said something like "it's the next left". He took the junction a little on the fast side but stayed on our side of the road. No fault recorded at all.
Another test and candidate was following signs but didn't get into the right hand lane of the dual carriageway in time so missed the first turning to the location. No problem, examiner was then quite insistent that he makes the second turning, which he did. A driving fault was recorded for awareness/planning or response to other road users (I forget which off top of my head) but other than that, the examiner re-planned what he wanted to do in the area and off we went.
Both of the above during the independent drive section, so if your examiner behaved they way you say and for no good reason then you would have grounds for a complaint / appeal as they should not be slamming the brake on just because you've missed a turn.