You're misunderstanding. The point is absolutely not that the fitness/accident correlation must be fictitious. It's that the fact that it exists exists suggests that the fitness/cardiovascular-mortality link may not be as direct as previously understood.
It might be co-causal, for example: to take your list, maybe "making poor decisions" has a bigger impact on cardiovascular health than we thought.
Kinda like how wine after dinner improves health outcomes. The kind of people who can afford to regularly drink wine, but not a lot, also have more access to healhtcare.
Also riding horses makes you healthier! (it’s a proxy for wealth)
One could argue that high VO2max may just be another proxy for wealth. People who can afford to work out every day can also afford lots of other things that correlate with health and longevity.
It might be co-causal, for example: to take your list, maybe "making poor decisions" has a bigger impact on cardiovascular health than we thought.