Heat it up and oil oozes out of the crack..........
That being the case the crack has too go all the way to the cross drilled oiling holes. I would think xray shots would show that and would be enough to get Eagles attention, especially since the crank shows no other physical damage. Probably a $50.00 investment to get back some of the $500.00 plus original payment for the crank.
JMO
Zip.