Lo standard probatorio del “più probabile che non” nell’imputazione di un inquinamento tra presupposti applicativi, forzature e disattenzioni

The article examines the “more likely than not” standard in administrative investigations aimed at identifying the polluter and establishing causation in contaminated sites. Starting from the “polluter pays” principle and the evidentiary challenges arising in the absence of direct proof, the paper reconstructs the role of presumptions under Article 2729 of the Italian Civil Code as the necessary structure of inferential reasoning. The analysis shows that presumptive reasoning requires, also for public authorities, compliance with the criteria of seriousness, precision, and consistency, as well as with a two-stage analytical and synthetic evaluation within a binary inferential structure. Within this framework, the “more likely than not” standard is not an autonomous criterion but the outcome of the inferential process, distinct from both comparative probability and a merely assertive use of the standard, which distorts its function and undermines the accuracy of fact-finding and the legitimacy of administrative action.