I think it’s safe to say cracks in a structural member are always bad. I think the point the OP is making is that it looks like a manufacturing defect not the result of a crash.
It seems they have no automated optical inspection (AOI) system. Why? Theories. (1) Manufacturing site footprint availability. AOI on large assemblies with high throughput requirements may be extremely spatially and temporally inefficient as the need to control lighting means a substantial facility footprint may be required. (2) manufacturing operation build time pressures (3) assessments and claims by the casting equipment provider (4) the potential unavailability of an off the shelf solution suitable for parts of this scale.
Stable process control could eliminate the need, but AOI is relatively cheap insurance.