(Exodus 23:7) "and a clean one and a righteous one you shall not kill": If one testified against another that he worshipped the sun, and another, that he worshipped the moon, I might think that they combine (to constitute the necessary two witnesses) to incriminate him. It is, therefore, written "and a righteous one (i.e., 'technically' righteous) you shall not kill."
A Clean One and a Righteous One You
Mekhilta Tractate Kaspa 3:8