4.3. Standard of proof
Overview
Even though different concepts as to the standard of proof have developed in the case law of the boards, they all have in common that a judgement is to be made on the basis of the application of the principle of free evaluation of evidence.
The EPO standard of proof is generally the balance of probabilities. By way of exception, the standard of proof of the balance of probabilities is shifted to a standard of proof beyond reasonable doubt mainly in opposition where only the opponent has access to information (evidence) concerning, for example, an alleged public prior use.
Of note in particular are some relatively recent decisions containing lengthy observations on the standard of proof and the previous case law on this, namely: T 2451/13 on the meaning of "beyond reasonable doubt" and T 545/08 on the meaning of "balance of probabilities" in the boards' case law; the latter decision, the board considered the matter in the general context of the law of evidence, concluding that a probability as low 51% would not suffice.
See also T 2466/13, in which it was likewise found that there was no need to decide on the applicable standard of proof. In the same vein, see T 768/20 and T 660/16 citing in particular to T 545/08 (points 8 and 11 of the Reasons).
- T 1708/18
Catchword:
1. The issue of which standard of disclosure applies when assessing the legal question of novelty and the issue of which standard of proof applies when assessing evidence and factual questions are distinct and unrelated. The fact that the standard of disclosure required for a finding of lack of novelty (or for allowing an amendment to the application under Article 123(2) EPC) is the standard of a direct and unambiguous disclosure is immaterial for the question of what standard of proof applies when considering evidence and factual issues in the context of novelty (or inventive step) (see point 16). 2. The standard of proof generally applied at the EPO for deciding on an issue of fact is the balance of probabilities. According to this standard, the EPO must base its decisions on statements of fact which, based on the available evidence, are more likely than not to be true. This standard also applies when examining factual issues in the context of novelty (see point 14).