With all of the walking dead, there is one scene that got my attention and I am sure yours too. Christian is holding Aaron by the campfire. So, the ghosts have the ability to manipulate their surroundings.
Also, Miles was very interested in Claire throughout the episode. Since Miles can commune with the dead, I wonder if he knew something? Did we just witness a Sixth Sense moment? Did Claire actually die in the previous episode when her house went kaboom? Could it be that her connection with Aaron allowed her to be manifested physically until she met with dear old Dad?