Question juridique clé
Whether the expertise-based damage assessment was sufficiently reviewable and lawful under Art. 42(2) CO and arbitrariness standards
Solution extraite
The cantonal review court had wrongly refused to examine the attacks on the expertise; the case must be reconsidered on that point.
Motifs extraits
The burden of proving damage remained with the plaintiff; the defendants were entitled to challenge the expert evidence, and the review court's refusal amounted to a denial of justice. The expert tables were insufficiently explained, and the method raised serious doubts because of aberrant results.