I luckily found a crack on anther pair of cranks that were the older Dura-Ace ones that have the "squarish" appearance.

I was changing all my stuff from one frame to another, and decided at the very last second to give the cranks a full clean before I put them on the new frame, then I saw a small crack inside the spindle hole which slips onto the axle.

I obviously chucked them.