No news here ...
The story: "The heat shield cracked whilst under stress testing specifically designed to see if it would break".
Reason: Original design flaw or (more likely) material develops age related changes - like microfractures or changes in structural properties - after standing at the back of a warehouse for ten years ...
This is all at the limit of space exploration technology and finding flaws before wasting one meelion/beelion dinar is what testing is designed to do. Test, inspect, learn, check budget, fix flaws, check budget again, repeat ... Ultimately spend as little as possible whilst still convincing the team "We're not at home to Mr Cock Up"