I don't think this reflects a flaw in LLM's at all. It is true that Paul Newman is not "known for" having alcohol problems. Paul Newman is known for acting, and salad dressing. Paul Newman has been "known to" have had alcohol problems, which formed as a question correctly one-shots accurate results for me across a few common LLMs. Someone like Betty Ford could be "known for" having alcohol problems. Paul Newman's alcohol problems are relatively specialized knowledge.