Saints D does not get 6 points because they weren't on the field...Meachum will get points for an offensive fumble recovery because thats what it was,,your offense stays your offense and does not become your defense on a play like that...same reason why points aren't taken away from Defenses when a fumble or interception is taken back for a TD...under that theory the defense who scored would become the offense once they intercepted or recovered the fumble and all points scored should go to the offense....just doesnt work that way
I think this is a good point, there should be a defensive td. If the offense throws a pick 6, the points certainly count against the defense, even if they aren't on the field. If the offense can be the defense and give up points for a touchdown, the offense should be able to be the defense and get credit for scoring a touchdown while in a defensive mode. Once the other team is in possession of the ball, whoever is on the field becomes the defense.