The author tells us that anger temporarily raises BP, and that people who are easy to anger have permanently higher BP, and since high BP is correlated with HD, we know that HD can come from physical factors.
This is a causality flaw- we know that these things are related, but not that any of them cause others. E exploits that flaw- it suggests that there is a common cause for high BP and being quick to anger, rather than that one of them causes the other.