[rando]

With your smaller bets on flop and turn he might well have you on a busted low and/or flush with two pair. I figure he has a K or straight at worst, so your call should be 100% for metagame purposes to set up similar river lead checks in the future when you actually have nut hands. Surprised he did have the boat actually... PSB on the river I figured he would show a str8 or flush (more likely) instead, a boat would perhaps merit more of a value bet, especially a strong one when AA is probably not in your hand based on the betting esp preflop.