Tire Sidewall problems of the 2002 Toyota Tundra

I purchased 4 new michelin p245/70 r16 from costco 12/5/2011with 31250 miles. I am a career auto mechanic for 39 years at an independent auto shop (retired, due to disability, 9/2011). I noticed sidewall cracking within about 2 years, but dismissed it because I have never heard/seen an air pressure loss due to sidewall cracking. The cracking worsened over the years, but the air pressure was even for all 4. Fast forward to 2020, I noticed my rf tire very low, looked for punctures, none found while submerged in water. November 2022 the rf tire was totally flat (parked). I found the sidewall had failed. This was a first for me in my experience. I certainly do not trust the remaining tires. I found a recall on the same brand/model but not my size. I have only 13350 miles on these tires. Tread is very good. I don't drive this truck often, but I maintain my vehicles well. Air pressure has been maintained at 40psi, 4psi under the max. Pressure. In my opinion this is an obvious case of a defect in materials. I have not contacted michelin yet.

The two front tires wore prematurely. As a result there were cracks on the side wall of the tire. The consumer was concerned that a blowout will occur. Please provide additional information.