Whether K.________ had standing to oppose N.________'s decision as another accident insurer.
No. In a pécuniary dispute between insurers, the second insurer may not itself file opposition against the decision notified to the insured.
Art. 78a LAA reserves insurer-versus-insurer disputes to the OFSP, while the insured may oppose a refusal decision under Art. 52 LPGA. The second insurer may be informed of the decision but lacks opposition standing.