OK, here's something that doesn't make sense...
At the end, they reprise the hospital scene from "The Invitations" with the doctor, this time with George as the patient. The same doctor that previously told George that Susan died tells George that his body was in an advanced state of atrophy due to a period of extreme inactivity.
But in the scene before George falls down the stairs, he is playing Frisbee golf.
Therefore, I charge that this is an inconsistency - playing Frisbee golf, then being told his condition is due to physical inactivity.
Zing.