Alternatives to english legal maxim hard cases make bad law

Are there any alternative idioms or phrases, equivalent to the english legal maxim "hard cases make bad law" best suiting the context of the following sentence?

I deeply sympathise with the unfortunate victim, but hard cases make bad law. It is not the within the discretion of the judge to let sympathy lend weight to the evidence.

https://www.phrases.org.uk/meanings/hard-cases-make-bad-law.html