Go and read the Constitution again, specifically Article 35.5.1. That will give you the exact text of a judge's oath. A judge upholds the Constitution and the laws not "God's Law".
If a judge has sworn to uphold the Constitution, then that includes Article 40.1 as outlined in my post above, that Article does permit a judge to make distinctions between a Garda and a member of the public. It is not unconstitutional.