Earlier quoted context omitted.
I'm not sure where you looked, but https://github.com/commaai/openpilot states it very clearly: "openpilot observes ISO26262 guidelines, see SAFETY.md for more detail."
Yes, but what does "observes" ISO26262 mean? The words I would want to hear before plugging this into my car are, "meets", "complies with with", or "certified to ISO26262."
ISO26262 compliance is really heavy and requires enormous amount of documentation and requirements tracking.