In my opinion, it was Elohkar's fault. Kaladin didn't foresee the consequences of challenging Amaram and was caught up in the moment. It was Elohkar that made a big deal of it and let Sadeas get away. He could have caught Sadeas first then explained the rules to Kaladin after. Kaladin did save Adolin and Renarin, so I think he should have gotten some leniency.