None of those three links supports the Daily Mail claim that smoking half a joint can cause sudden death.
They do say that prolonged, chronic use could impact the cardiovascular system, something I did not deny, but none support the "sudden death by cannabis poisioning" claim.
In fact, the second link says...
"A large cohort study showed no association of marijuana use with cardiovascular disease hospitalization or mortality."
And the subject in the third link smoked 20 tobacco cigarettes a day. I wonder what that does to your cardiovascular system?