The thing is, the section between those parallel die cracks does seem to have shifted some, most noticeable at the end AWAY from the rim in the head. It appears to be higher than the area directly to the left of the cracks. If so then this WOULD be a retained cud, just not a very impressive one.
Superficial cracking with subsurface deformation is fairly common in dies. That's why you get bi-level die cracks and that's why there's no reason to think this is a retained cud.