Your absolutely right, about me calling rather than raising if I thought I was ahead. My reason for calling was two-fold: (1) I did think he was bluffing and that my Ace-high might have been good, but I wasn't sure and, ill-regardless of whether I was good or not, (2) I wanted to see his cards and was willing to pay for it. Remember in my preface I mentioned that in the 1-1/2 orbits leading up to this series I hadn't seen him to showdown, but he was involved in most of those hands. I just needed to see if he was on a nice run of cards or very loose with his starting hand selection. Nice pickup!
As a general rule, the ace high call down on the flop is done when in position, and it is done for only one street. If he bets the turn as well, you give up and fold, because he's rarely firing two bullets. The intent is to see if he bets the turn. If he checks, he was probably bluffing the flop and didn't hit the turn, so you bet the turn and take it down. Otherwise, you just fold.
As played, it violates those two criteria, so I wouldn't do it. I much prefer a check raise.