why did he keep betting pot?

Game #6207406473: Omaha PL ($1/$2) - 2008/07/22 - 15:50:13 (UK)
Table "Developed" Seat 1 is the button.
Seat 1: Slim ($92.86 in chips)
Seat 2: Greenday7 ($205.95 in chips)
Seat 3: broadway9 ($210.25 in chips)
Seat 4: svetlana ($287.70 in chips)
Seat 5: guenh ($225.55 in chips)
Seat 6: Hoobi ($214.40 in chips)
Greenday7: posts small blind $1
broadway9: posts big blind $2
----- HOLE CARDS -----
dealt to Greenday7 [Ad 6h Kd 8d]
svetlana: folds
guenh: folds
Hoobi: folds
Slim: raises to $7
Greenday7: calls $6
broadway9: folds
----- FLOP ----- [8c 8s 8h]
Greenday7: checks
Slim: bets $16
Greenday7: calls $16
----- TURN ----- [8c 8s 8h][5s]
Greenday7: checks
Slim: bets $48
Greenday7: calls $48
----- RIVER ----- [8c 8s 8h 5s][Ah]
Greenday7: checks
Slim: bets $21.86 and is all-in
Greenday7: calls $21.86
----- SHOW DOWN -----
Slim: shows [Qh As Qc 6c] (A Full House, Eights full of Queens)
Greenday7: shows [Ad 6h Kd 8d] (Four of a kind, Eights, Ace high)
Greenday7 collected $184.72 from Main pot
----- SUMMARY -----
Total pot $187.72 Main pot $184.72 Rake $3
Board [8c 8s 8h 5s Ah]
Seat 1: Slim (button) showed [Qh As Qc 6c] and lost with A Full House, Eights full of Queens
Seat 2: Greenday7 (small blind) showed [Ad 6h Kd 8d] and won ($184.72) with Four of a kind, Eights, Ace high
Seat 3: broadway9 (big blind) folded before Flop (didn't bet)
Seat 4: svetlana folded before Flop (didn't bet)
Seat 5: guenh folded before Flop (didn't bet)
Seat 6: Hoobi folded before Flop (didn't bet)