Question juridique clé
Whether the purchase price was validly set off against a fee claim before 14 February 2006
Solution extraite
No valid set-off was established; the alleged compensation declaration was not proven and the fee claim amount was unresolved.
Motifs extraits
Set-off under Arts. 120 and 124 CO requires a declaration and an existing compensating claim. The record did not establish any clear unilateral declaration, and compensation cannot operate for an unproven claim amount.