I know this is a 2 month old post but thought I'd add one more point: Why does the insulation contractor care? He doesn't fail electrical insp. NEC and NEMA violations are irrevelent to him as long as he can back up/substantiate his answer that it's "code compliant"; after all, he just did what the customer wanted. (I've had this prob on a smaller scale and I don't agree with him, just playing devil's advocate)
It goes like this: "If I say that it doesn't meet Code, they won't pay me to do it; when they find someone who tells them what they want to hear, they'll pay HIM instead of me".