Question juridique clé
Who was the worker's employer in the triangular service arrangement: X.________ SA or the broadcaster?
Solution extraite
The worker was bound by an employment contract exclusively with X.________ SA, not with the broadcaster.
Motifs extraits
X.________ SA knowingly let the worker perform for the broadcaster while paying his salary itself; this conduct established an employment contract under Art. 320(2) CO. The broadcaster's role was consistent with labour leasing, where direction is delegated to the hirer.