Question juridique clé
Whether the cantonal court could rely on the rheumatology expert report rather than the treating physicians' opinions.
Solution extraite
The expert report remained probative; the treating physicians did not identify objective elements ignored by the expert that would undermine the conclusions.
Motifs extraits
The court repeated the settled distinction between treatment and expert mandates. A contradictory opinion from treating doctors alone does not justify disregarding a court-ordered or administratively ordered expertise or reopening evidence.