I think you're over-estimating how much some people care.

I have had coworkers say "Oh I don't know, Claude added that" in response to questions like that without even a hint of shame or self-reflection.

Sure, some people have no self awareness. In that case you can change your approach, if you are a manager or otherwise invested in the company you can put pressure on them to increase the quality of their work and to own the things they submit. Bring up specific examples of poor quality work, errors in documents/messages, etc.

Or if you don't care you can just ignore this persons messages.

I had someone submit a PR that was 3000 lines of shell scripts. Totally useless crap. I tried repeatedly asking him why he made particular choices and it was so painfully obvious that he had absolutely no idea and was just inventing bullshit answers. I would rather he have just said "I don't know, Claude added that", then tell obvious lies to my face.