He could have a sight with a few different options for a dot size,a Tee, a Chevron, etc.
Or the reporter could be a dingus ;-)
Not so legendary. Put the dot on the target and pull the trigger. Most red dots are 2 moa. That is a 4 inch dot at 200 yards. AR 15s shoot flat from 0-200 yards . No hold over or compensation needed. The bullet impacts where the dot is.