Yeah Cliff you don't want to be the guy who ok'd non stainless when a fan lands on someone!

you sign something, there is a paper trail

you'd be well advised to do nothing orally with this guy - make everything a written change order & document with Emails, faxes, whatever

When it's a safety issue...stick to your guns!

My impression of you is your honor and integrity are beyond reproach and you'll always do what's right regardless.

But in case you find yourself under pressure always remember, it's better to risk losing your job than to risk lives and criminal/civil charges/suits that can destroy you and your family for ever because some a-hole would not or could not do his job.