KK vs. possible rock

[eviljeff]

villain is ~9/2/1 after 60 hands

PokerRoom 1/2 Hold'em (9 handed) converter

Preflop: eviljeff is UTG with K[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/spade.gif[/img]
<font color="#CC3333">eviljeff raises</font>, <font color="#666666">6 folds</font>, SB calls, <font color="#666666">1 fold</font>.

Flop: (3 SB) 4[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets</font>, <font color="#CC3333">eviljeff raises</font>, <font color="#CC3333">SB 3-bets</font>, <font color="#CC3333">eviljeff caps</font>, SB calls.

Turn: (5.50 BB) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">eviljeff bets</font>, SB calls.

River: (7.50 BB) 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, eviljeff furrows his brow

against an unknown this is an instabet, but this guy's stats made me pause. granted, I only have 60 hands on him, but if he is a rock what do you think his hand range is at the river?

I'd say..
99 (or less likely 44 or 22) - afraid of flush
TT-AA
non-nut flush - fearing nf
slowplayed nf

anyone bet the river and fold to a c/r?