Ignoring the blocking bet

BR: $49,421

I'm still prepondering this following hand.

Party Poker Pot-Limit Hold'em, $ BB (6 max, 5 handed) converter

SB ($887.25)
BB ($449.25)
UTG ($1004.90)
MP ($612)
Hero ($739)

Preflop: Hero is Button with Ad, Ks. SB posts a blind of $3.
2 folds, Hero raises to $21, 1 fold, BB calls $15.
Flop: ($45) 4h, Ac, 4d (2 players)
BB checks, Hero bets $43, BB calls $43.
Turn: ($131) 2c (2 players)
BB checks, Hero bets $129, BB calls $129.
River: ($389) 7c (2 players)
BB bets $100, Hero calls $100.
Final Pot: $589

BB has Th Ah (two pair, aces and fours).
Hero has Ad Ks (two pair, aces and fours).
Outcome: Hero wins $589.

Did I misplay this river? Was I supposed to push? Let's do some simple math given my analysis of my opponent, who I saw as fairly weak. I think I'm against a dominated ace 75% of the time -- and 50% of the time (not of this 75%, but total) they will be calling this push. There's a 5% chance this is a bluff that won't call a push. And 20% of the time I'm behind to a set, two pair, flush. He has $156.3 behind.

EV of a call: +489.0*0.8 -100*0.2 = +$371.2
EV of a push: +645.3*0.5 +489.0*0.30 -256.3*0.20 = +$418.1

Hmmm. Interesting. On a side note I was goofing off at NL $400, and managed to make two basic blunders; SNAFUs I haven't made since I was playing NL $100. Yuck! Maybe it's time to take a day's break.