Two Innocents and One Stolen Kidney

 

William needs a kidney but a donor can't be found and he has little time. William's father Charles is a transplant surgeon. Charles tracks down a suitable match named George. Instead of asking, Charles takes George's kidney against his will by knocking him out and surgically removing his kidney. William's doesn't know how the kidney was acquired. Charles transplants the kidney in William. What Charles didn't know is George only had one good kidney and will die without his kidney. William will probably die in another surgery but if he doesn't, he will still die soon because he needs a kidney.

Who should get the kidney?