Standard push on river?

[Logik]

CO has only been playing one orbit; no reads. He has not gotten to showdown yet, nor has he really gotten out of line.

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) converter

CO ($13.20)
Hero ($48.60)
SB ($37.25)
BB ($44.65)
UTG ($22.80)
MP ($26.50)

Preflop: Hero is Button with T[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">2 folds</font>, CO calls $0.25, Hero calls $0.25, <font color="#666666">1 fold</font>, BB checks.

Flop: ($0.85) K[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, <font color="#CC3333">CO bets $0.25</font>, <font color="#CC3333">Hero raises to $0.75</font>, BB folds, CO calls $0.50.

Turn: ($2.35) J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">CO bets $1</font>, <font color="#CC3333">Hero raises to $3.75</font>, CO calls $2.75.

River: ($9.85) 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
CO checks, <font color="#CC3333">Hero bets $8.45</font>...


The river is putting him all in.

Standard, or chip spewing?