The MSD representative would have been fine to say that the gas was not at harmful levels. The public needs to understand that the amount of the substance, in addition to its identity, defines a harmful situation. But the article's information was that the gas was harmless and constituted a mere suffocation hazard. This is grossly wrong, although it can be well appreciated that the truth can sometimes be fodder for ambulance chasers. Misinformation contributes to misunderstanding.
Nitrous oxide is used medically as an anesthetic.
It's even in a can of whipping cream. Check it out on a label sometime. Many plumbers know the danger of dumping acid cleaners down drains because this can release deadly hydrogen sulfide gas. We can't expect all response personnel to know every harm about every compound on the planet. Not a single chemist can claim this anyway.