Can You Trust Your Credit Card Car Insurance? - Flat Tire Follow-Up

"Tire damage, unless damaged by fire, malicious mischief or vandalism, or stolen or unless the loss be coincident with a covered loss [is not covered by, for lack of a better term,  credit card car insurance]."

That's the explanation from the Chubb Insurance Company which handles claims for my credit card company, Citi Bank. 

I've rented dozens of cars, domestically and internationally, always relying on the car insurance provided by my credit card and refusing any additional insurance from the rental agent, but this is the first time I've had a claim.  And that claim was denied. (Click this link to read about our misadventure with the tire in Dinan, France.)