Similar issues were found on the early M62 engine on the BMW 7'ers (had a couple of 740's in the past)The AJ V8 is made in capacities I believe ranging from 3.2 litres to 5 litres, the latter using thin wall pressed liners to accommodate the required bore size and is unique to Aston Martin. The 3.2 is made by Ford in the states and used in the Lincoln marque among others. Jag/LR engines are made in the Ford plant at Bridgend supposedly in a dedicated part of the plant.
The engine was designed to use nicasil liners. Early engines suffered failures of the nicasil coating blamed on high sulpher fuel. A switch was then made to conventional cast liners. I would guess that, like the 4.0 & 4.6 LR V8, this must have weakened the block.