When it comes to civil claims, the court works on the balance of probabilities rather than the criminal standard of proof. A judge does not need scientific certainty in order to reach a conclusion, and the court must decide what is more likely than not based on the evidence available. 

Once an outcome is known, particularly an adverse one, it often appears more predictable than it was at the time. This is known as hindsight bias. It is a well-recognised cognitive bias in legal analysis, and it has a direct impact on how cases in aesthetic medicine are interpreted.

One of the most difficult positions an expert witness can find themselves in is this: you have completed your analysis, agreed a common approach with the opposing experts, and the results are not what your instructing party hoped for.