And where it says "Other passengers became agitated...".... were those other passengers her relatives? I think the implication in the article is that the plane was in an uproar over the flight attendant's behavior, but my guess is that it was her family members who knew she had a medical condition that were the ones who were agitated.

Just think about it....being given air with a higher concentration of oxygen won't stop a heart attack. An oxygen tank could be beneficial for many things... but not that.