What happened was this. After a period of deliberation, the Judge called the jury back in and asked them if their was a decision on which they all agreed. At that point, I imagine His Honour was told that there was a 10:2 split. He probably sent them out a few more times before ordering he would accept a majority verdict on which 10 of them agreed. In the deliberations thereafter (they have to deliberate for at least 2 hours after a majority direction), one of the two changed their mind.