Is it a failure if you are caught on tape in disguise and they still have no idea who you are? It isn’t perfect, but they did kill the terrorist without getting caught. In fact, they slipped out of the country before anyone knew he was dead. I’d say that is a success.
Actually, the Dubai police caught the people without their disguise. The photos of the agents published worldwide are real.
Dubai also claims to have transmitted their retinian IDs to Interpol.