It was a very questionable decision in that Rees landed more shots in every round of the fight, was the much busier guy in every round, and landed the cleaner shots. I saw Rees winning almost the rounds. The only rounds I could give Crolla were the 3rd and 11th, and even in those rounds, Rees outlanded him.
Crolla had the crowd in his favor big time in this fight, and the outcome was not surprising. Crolla was getting cheered even when he missing shots; whereas the crowd was deathly silent each time Rees landed, which quite often.