im going to let you spend your presumably last moments being in excruciating pain
because im your friend
They were the best of buds until Anakin killed the Youngling. Mace Windu. And plotted to kill all of the other Jedi.
Obiwan didn't have the heart to deliver the final blow. But he didn't need too, Anakin was good as dead anyways on that lava shelf. And what if he saved him? Society belongs to the Empire now. How would a wanted man help his "friend" while on the run?
Weird how so many here are supporting saving a child murder who abused his wife and nearly killed the Obiwan.