As I recall, Taleb specifically used the example of a flu pandemic not being a black swan event as it is a known (and modelled) possibility.
Pedantic I know, but the reference to black swans is because they were thought not to exist (all swans are white), thus a "black swan event"
The comment that "If the BIS announces an increase in OTC Derivatives in a couple of weeks, a total financial collapse is guaranteed." is alarmist nonsense. Most OTC derivatives are simple interest rate swaps, foreign exchange swaps/forwards etc.
I note he is president of a gold company - wouldn't be talking up his positions by any chance?