The simple fact is, the minimal number of tyres ( mind you, that number is pretty small considering the sheer number sold worldwide) that blow out side walls is due to misuse, and strangely enough, it seems to be the PARK version.
If there is a manufacturers fault, you are covered.
If a park version tyre blows out on rough concrete ledges, when it is designed for PARK use with smooth coping, is that an issue with the tyre?
Unfortunately warranty does not cover ripping open a sidewall on that besser brick ledge that you were grinding.
Incorrect pressure, ( yes there are tell tale signs), mounting tyres on rims with screwdrivers, ( yes, I have seen it)
and riders using the wrong tyre for the style of riding.
Hell, I have seen guys try and run a MAC 1 ( flatland tyre) for street, and wonder why it blew out...
But yes of course that is completely the tyres fault.