The graphic shows Alston as the 50 cal gunner. Has it been definitively established that he, rather than Fred Short, was the gunner on 13 March?
Yes. in fact March 13 was the only time Alston was with Kerry in combat. All other testimony from Alston about Kerry's "courage under fire" is based on reports Alston heard from other people (possiibly with initials JFK) or about a different guy (Lt Peck)