Newhizzle v. Joe Cassidy 500/1k HU match

[shaniac]

PokerStars Game #10184772587: Hold'em Limit ($500/$1000) - 2007/05/30 - 14:54:30 (ET)
Table 'Buda' 10-max Seat #3 is the button
Seat 3: newhizzle ($130306 in chips)
Seat 4: BUTCH ACIDY ($156600 in chips)
newhizzle: posts small blind $250
BUTCH ACIDY: posts big blind $500
*** HOLE CARDS ***
newhizzle: raises $500 to $1000
BUTCH ACIDY: raises $500 to $1500
newhizzle: calls $500
*** FLOP *** [Js Ks Ac]
BUTCH ACIDY: bets $500
newhizzle: calls $500
*** TURN *** [Js Ks Ac] [Ah]
BUTCH ACIDY: checks
newhizzle: bets $1000
BUTCH ACIDY: raises $1000 to $2000
newhizzle: calls $1000
*** RIVER *** [Js Ks Ac Ah] [9h]
BUTCH ACIDY: checks
newhizzle: checks
*** SHOW DOWN ***
BUTCH ACIDY: shows [Jh Jd] (a full house, Jacks full of Aces)
newhizzle: mucks hand
BUTCH ACIDY collected $7998 from pot
*** SUMMARY ***
Total pot $8000 | Rake $2
Board [Js Ks Ac Ah 9h]
Seat 3: newhizzle (button) (small blind) mucked
Seat 4: BUTCH ACIDY (big blind) showed [Jh Jd] and won ($7998) with a full house, Jacks full of Aces

Can someone explain the river check? I doubt is Mark more likely to bet and call a check-raise than to pay off a value bet.