I know you guys don't watch Talking Dead, so you didn't see the guy who plays the soldier being interviewed.
They asked him why he killed the men in the supermarket and he said that storyline was straight out of the comics. That was the group he and his family were rolling with, and once when he returned from a supply run, he found that they had raped his wife and daughter while his son was made to watch. These men were his friends and neighbours before the apocalypse. So anyway, naturally, he killed them all.
In a twist of fate, it was the first time his family saw him being a soldier, rather than soccer dad who takes out the trash. They were terrified, and his wife left because she said that he was no better than the rapists. Of course, his entire family ended up getting eaten when they were on their own. I kind of felt sorry for the soldier.
The fake scientist was also interviewed. He said that his character saw the soldier about to kill himself in front of his dead family, and quickly realised what lie would work with him.