Just because it’s generally possible for the bladder to rupture before the muscles give out, it’s certainly not impossible. A myriad of conditions or even just genetics can lead to a physically weaker bladder.

I think it’s a bit bold to say that absolutely 100%, no exceptions, that the muscles will always fail first. Even if that’s true 99.99% of the time, there’s just far to much variance in human bodies to rule it out, I would think.