He is probably trying to, correctly, imply that heart attacks at 51 are an anomaly given how much we know about heart attacks and how accurately tests can predict them. Especially for a person of the deceased's means.
The OP is also factually correct: "The current generation of American children may be the first not to live as long as their parents". [1] [2]
I didn't down vote you but I think your initial down votes were based on two things:
1) you stated your opinion as a fact. There is some research to point to shorter life expectancy but stating it as a fact that will happen no matter what seems a little strong.
2) you state that life expectancy will "plummet". Plummet indicates a very large dropoff. From what I've seen, some respected paper suggest that life expectancy might dip by a year or so.
But to have a say 10 year drop, which is what plummet would indicate seems rash as no credible scientists are predicting that.
I think he is trying to imply that someone having a heart attack at 51 should not be considered normal, unless you smoke.
My father is very old, there are over 20 or so of his friends that died in his 50s. All of them were hight smokers. Not a single "non-smoker" friend died on his 50s, in fact they seem to get by at least to the 70s.
Things like lung cancer were almost unheard of before people started smoking(before WW less than 3% of the population smoked).
