Both the amicable expertise and the unilateral expertise constitute an element of proof since the report, although not having the value of an expert opinion, has been submitted to the parties for discussion and contradiction (1 st Civ., 13 April 1999, Bull., I, n ° 134, p. 87, concerning an expert report wrongly qualified as an amicable expert; Com., February 15, 2000, appeal n ° 97-16.770; July 10, 2001, appeal n ° 98-18.188; 1 re Civ., September 24, 2002, Bull., I, n ° 220, p. 169; March 11, 2003, Bull., I, n ° 70, p. 53) and that these had the opportunity to discuss the contents (2 e Civ, 7 November 2002, Bull II, No. 246, p 191;… 3 e . Civ, 23 March 2005, appeal No. 04-11455).
The probative value will be all the stronger if the unofficial expertise will have been carried out contradictorily (3 e Civ., October 29, 2003, appeal n ° 01-11.004, in the case of a genuinely amicable expertise to the operations of which the parties had been convened and had participated, so that they had taken place in a contradictory manner and that no reservation had been expressed by the parties as to the responsibility of one of them; in the same sense: 1 re Civ., May 22, 2001, appeal no.98-14.471).
It was stated that “any amicable relationship may be valid, as evidence, as long as it is subject to free discussion by the parties” (1 st Civ., September 24, 2002, Bull., I, n ° 220, p. 169; March 11, 2003, Bull., I, n ° 70, p. 53), but the court must still have examined whether the opposing party had been able to assert its point of view (3 e Civ., October 3, 1991, Bull., III, n ° 221, p. 130).
A party may rely on an unofficial expert report, which constitutes admissible evidence as to the date of knowledge of the fatal defect by the purchaser, even if it is established after the filing of an inspection report. judicial expertise to criticize it (1 re Civ., March 19, 1991, Bull., I, n ° 101, p. 66). This relative favor for extra-judicial expert opinions, provided that the principle of contradiction is respected at the stage of invoking their results, can be explained by the saving of time and the lower cost which result therefrom for the parties.
Informal, unilateral or amicable expertise is only subject to the adversarial principle when it is invoked in the proceedings (2 nd Civ., June 24, 2004, appeal no. 02-16.401).