Tell that to a photo-finish loser in the Kentucky Derby.
If a loser believes the decision is wrong and takes it to court, do you expect the court would politely accept their own photograph of the finish as evidence? If that were true there probably would have been several cases already, each with their own photographs purporting to show who really did win.
But in fact the evidence that counts is when they bring in the expert technician/engineer team that desinged, installed, and operated the photo finish camera. Reality isn't the photograph, it's their sworn testimony of what the picture shows.
As Garry Winogrand said about pictures, "They're mute, they don't have any narrative ability at all, you know what somethig looked like, but you don't know what's happening."
Of course what you may not be aware of is that a photofinish camera doesn't take one photograph, it produces a composite of many photographs, all at the same place but at different times. Because of that it is, with multiple pictures, a narrative that tells what happened. But its the expert testimony explaining it that will be the evidence that decides the case. And not one of the pictures alone would be useful, or even recognizable.