Calldown in Huge Pot

[Scotch78]

BB is 59/1.5/41/.5 (VP$IP/PFR/WSD/AF) over 60 hands. On one occassion each, I've seen the CO donkbet with crap and overplay AA.

How standard is this without a more solid read on the CO?

PokerStars 2/4 Hold'em (8 handed) FTR converter on zerodivide.cx

Preflop: Hero is MP1 with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img]. CO posts a blind of $3.
UTG calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, CO (poster) calls, <font color="#666666">2 folds</font>, BB calls, UTG calls.

Flop: (9 SB) 8[img]/images/graemlins/club.gif[/img], 2[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">BB bets</font>, UTG calls, Hero calls, CO calls.

Turn: (6.50 BB) Q[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">BB bets</font>, UTG folds, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">CO 3-bets</font>, BB calls, Hero calls.

River: (15.50 BB) 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, Hero checks, <font color="#CC3333">CO bets</font>, BB calls, Hero calls.

Final Pot: 18.50 BB

Scott