One of the ways to tell a person who has actually read the Bible, old or new testament, is they don't get drawn into discussions about what is or isn't in the Bible.
Most people can't tell a King James verse from a line from King Lear. Their knowledge of history is no better, for much the same reasons. They are trying to recall something they learned in elementary and high school, and distinguish that from a dozen or so movies that got it wrong.
Util someone puts them on the spot, they haven't given a thought to what's in the Bible, since their last Sunday school class.
What does "lack of morals" mean?
It's highly doubtful this experiment was done using a King James bible, but I don't disagree with your points. On the other hand, there are pockets of people who read the bible fastidiously. I came from such a background. We
knew what was in the Bible and still believed it. All of it and without apology. I was a fundamentalist and quite proud to be one. Being a fundamentalist does not equate to being an idiot any more than being a new-age woo follower does. I'd encourage those of you with little to no tolerance for such people to understand that, but I'm not into being pushy anymore, so believe what you want. (Not talking directly to you about that last bit Bronzeage, that comment was meant more for those who spoke disparagingly about fundies earlier).
The rationalization for a fundamentalist is fairly simple: If it seems horrible it's your fault for not understanding the big "god" picture. God has a right to do what he does, he's righteous in all things and we're not in a position to judge him.
The people in this video are very different from the average bible-belt fundie one is likely to meet. They might not be more likely to recognize OT passages like this, but they certainly wouldn't smile and be wow'd after the reveal. The rationalizations about "context" would start flowing immediately.