As I understand the history, Miller did not return from the war unscathed. He fell out of a wagon and sustained a severe concussion, which may have affected his personality.

Also, although Miller did withdraw from public life, I have never read that he actually renounced his convictions other than (of necessity) accepting that his calculations of the date had been erroneous.

I'm not saying you are incorrect about these points, only that I have read different versions of Miller's story.