Here is a TDX track Chelsea and I ran at Hastings Island when she was still a young dog and I was still a relatively inexperienced handler. Chelsea ran the track brilliantly and very much deserved to pass, but I screwed up as handler. She performed perfectly, but at the second article, indicated by the pink arrow, she was unable to retrieve the article. I think the article had actually fallen down a crack in the field and was out if reach of her mouth. I did see her halt and act as if she thought she had an article. Now if I had been doing my job as her handler correctly, I would have asked her to "wait" and gone up to her to see what she was fussing about. If so, I would have seen the article and picked it up and we would have been scored as having correctly found it. Instead I urged her to continue tracking. She obeyed and shortly afterwards the Judges whistled us off as having missed an article. She then completed the track with absolute perfection. (Now in Schutzhund tracking a missed article would simply be points off , so Chelsea would still have passed and probably with a score around 90. But in AKC tracking, a missed article is a flunk.)
 
I could have killed myself.

This track is the utmost of rarities, a track where the dog performed wonderfully and the handler performed OK, but (in my opinion) the judges screwed up by whistling off the dog while she was still working and was doing so very close to the track. The rules say that there is no time limit and the dog should be allowed to continue working so long as it is clearly trying to find the track and has not gone so far off that a re-find is beyond reach.
Chelsea had performed the first 5 legs of the track in an almost perfect manner, being off track only slightly at the first ditch, probably because scent does tend to pool into low places. The 5th turn was located in the middle of a triple ditch, with the next leg going right down the center ditch. Chelsea circled repeatedly, diligently seeking the track, but had passed over it several times without indicating it. This can happen if the dog happens to be breathing rather than scenting as it passes over the track. She was still working and had not tried to take me in any direction other than the correct one. The Judges whistled her off. I believe she would have solved the problem given a bit more time to do so. When re-started, she tracked perfectly the remainder of the track.
 
I could have killed the Judges.