Calling a steal (?) river bet with middlepair top kicker?

[cyg]

Villian is 25/14. Here's the hand:
Stack sizes:
UTG: $35
cyg: $51.75
Button: $103.20
SB: $50.80
BB: $63.30

Pre-flop: (5 players) cyg is CO with A[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/club.gif[/img]
UTG folds, <font color="#cc0000">cyg raises to $2</font>, Button folds, SB calls, BB folds.

Flop: J[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/diamond.gif[/img] Q[img]/images/graemlins/spade.gif[/img] ($4.5, 2 players)
SB checks, <font color="#cc0000">cyg bets $4</font>, SB calls.

Turn: 5[img]/images/graemlins/diamond.gif[/img] ($12.5, 2 players)
SB checks, cyg checks.

River: 8[img]/images/graemlins/heart.gif[/img] ($12.5, 2 players)
<font color="#cc0000">SB bets $10</font>, cyg calls.

Results:
Final pot: $32.5

My thoughts on him were that he either has nothing or the best he holds is a jack with either the same kicker as me or a weaker one.
Should I have folded the river instead?