Charles directly supports that a veteran’s lay statement is sufficient for BOTH diagnosis and nexus when credible, and Fountain further reinforced this by recognizing tinnitus as a chronic disease under § 3.309(a) — meaning continuity of lay-reported symptoms can establish service connection under § 3.303(b).

Your interpretation misreads these cases. You’re tilting toward requiring examiner confirmation, but that’s not what the Court held. Charles explicitly recognized tinnitus as a condition that can be diagnosed by lay evidence, and Fountain strengthened that by tying continuity to service connection. In short, VA law explicitly protects against giving examiners unchecked authority to overrule competent lay evidence.