You can only have one absolute moral principle; everything else must ultimately be contingent on not violating that core principle.
I am usually bringing this up on HN in the context of free speech, because I think free speech is a poor choice to make your absolute moral principle.
In this context, there's another example of a poor choice for an absolute principle.
Brotherhood, fraternity, loyalty to your group is frequently a good thing. Many things only work with trust.
But this is what it looks like when brotherhood -- loyalty to your fellow police officers, in this case -- is your absolute moral principle. Upholding the law and protecting the innocent come second to protecting your own.
https://en.wikipedia.org/wiki/Value_pluralism
And modern psychology and neuroscience appear to back it up.
Hegel was full of shit.