That is some bad info you got there.
In an inhome situation the "spread" of a shotgun load (00 buck would probably be the load of choice) will be almost a non issue.
Over a 5 yard distance, you arent going to get a fantastic spread pattern. Its not like a video game.
and a pump shotgun is more likely to malfunction for an inexperienced shooter in a situation like that. An AR that is properly maintained isnt likely to just fuck up after a shot or 1 of semi auto fire.
People who think racking a shotgun is going to scare someone away, or is a good idea is an idiot. The last thing you want to do in an actual home defense situation is give your position away and let them know what you are using. You have the home advantage and element of surprise when someone is kicking a door in. You dont want to give anything up.
also before someone says it. Warning shots and "neutralizing shots" are fucking retarded too. Dont do that or think that is a viable thing.
And for over penetration, most 223 loads are going to overpenetrate less than 12 gauge buck if you do miss.