I think you missed the point, "will often express very blunt concerns about quality/risks in emails or PRs" means he straight up communicates any issue without sugar-coating. Which is what you want from a conscious employee. If despite that someone higher up in the decision chain ignores the issue (in the case of safety risks, that is criminal negligence), to continue to fight this battle is pointless and would only mean risking one's career for nothing.

The beginning of the sentence:

> If my employer doesn’t heed my advice,

I think the OP’s assumption – or at least hope – is that if they identify a problem so severe that disclosure would be a serious liability, then their employer will heed their advice, and fix it. The shared goal is producing quality results, not covering anyone’s ass (either OP’s or their employer’s) when they don’t.