Exactly!!
From personal experience my best friend phoned me once at 1am telling me that a mutual acquaintance of ours had been spreading absolute
about me and I asked for proof. My best friend came with proof instantly, full proof, I then called that mutual acquaintance out.
Another time on a different occasion a different best friend told my family that my partner at the time was cheating (while I was in hosp literally on the brink of death yk) I was too out of it to deal with anything BUT there was proof and countless people came forwards after I regained my cognitive abilities to also provide further proof as well of my now ex cheating/threatening other women/faking being canadian/compulsively lying including my ex’s own best friend. I was shown messages, heard recordings and saw videos.
Always go on proof. Asking for evidence is no big issue. I personally am never put out if I’m asked for proof of something because proof is necessary you can’t trust ANYONE.