34K miles and you get 75% pro-rated towards new tires? Doesn't sound too bad to me. I'm at 27K on the bald Firestones that came with my truck and I'd be doing cartwheels if I got 50% of the cost.
Blowouts and accidents are what insurance is for. It's hard to believe that 3 tires instantly fell apart showing no previous signs but I suppose anything is possible. Getting 75% of your money back on a product that lasted this long is more than generous IMO.
If I didn't know better I'd guess the OP is a lawyer. Not trying to be a dick but things do sometimes just happen.