A Razz hand : betting on the river ?

[Ezqimo]

Full Tilt Poker Game #2451368242: Table Winnick - $2/$4 Ante $0.40 - Limit Razz - 2:52:14 ET - 2007/05/18
Seat 2: carpetman280 ($47.10)
Seat 3: Ezqimo ($36.40)
Seat 4: pipey9 ($76.20)
Seat 8: pshirley13 ($70.30)
carpetman280 antes $0.40
pshirley13 antes $0.40
pipey9 antes $0.40
Ezqimo antes $0.40
*** 3RD STREET ***
Dealt to carpetman280 [Ac]
Dealt to Ezqimo [7s 5d] [Ah]
Dealt to pipey9 [Kc]
Dealt to pshirley13 [Qh]
pipey9 calls $1.50
carpetman280 calls $1.50
*** 4TH STREET ***
Dealt to carpetman280 [Ac] [2d]
Dealt to Ezqimo [7s 5d Ah] [4c]
Dealt to pipey9 [Kc] [9s]
carpetman280 checks
Ezqimo bets $2
pipey9 folds
carpetman280 calls $
*** 5TH STREET ***
Dealt to carpetman280 [Ac 2d] [2s]
Dealt to Ezqimo [7s 5d Ah 4c] [6s]
Ezqimo bets $4
carpetman280 calls $4
pipey9 stands up
*** 6TH STREET ***
Dealt to carpetman280 [Ac 2d 2s] [3h]
Dealt to Ezqimo [7s 5d Ah 4c 6s] [7c]
Ezqimo bets $4
carpetman280 calls $4
*** 7TH STREET ***
Dealt to Ezqimo [7s 5d Ah 4c 6s 7c] [Qd]
Ezqimo checkscarpetman280 checks ? What should I do ? Why ?
*** SHOW DOWN ***
Ezqimo shows [Qd 7s Ah 4c 6s 7c 5d] (7,6,5,4,A)
carpetman280 mucks
Ezqimo wins the pot ($26.60) with 7,6,5,4,A

[nsidestrate]

I'm betting the river here 99% of the time. Good stud players won't fold the river with any kind of made low and if he caught better than a 7-6, he would have raised 6th. I think you are missing a bet here.