Jax is always seen wearing white Nike Air Force 1 sneakers throughout the entire series, which is a very notable part of his look. However, in the pilot, he is seen wearing black Adidas, low-top sneakers.
Scott Glen was originally supposed to play the Clay Morrow role. All of Glen's scenes in the pilot got recorded again with Ron Perlman. In the explosion scene at the Mayan depot in the end, it is possible to see Glen (and Emilio Rivera, who would become Marcus Alvarez.