不偏不倚-----hold the scales even

例句：
A: The riot was said to be caused by the unfair judgement.
据说该暴动是由不公平的判决所引起的。
B: No, I don't think so. I do believe that the umpire held the scales even.
不，我不认为如此，我真的相信该裁判的判决不偏不倚。

注释：
be caused by 由......引起
unfair judgement 判决不公