PLO beginner: Good chase, or a complete donk?

[soulvamp]

Trying to learn to play PLO. Was in decent shape in this $10 tourney, about sixth with 20 players left, top 5 pay. And then this hand got me. I knew what he was betting, but I just had so many outs I couldn't let it go:

Stage #994855162 Tourney ID 1926590 Omaha Multi Normal Tournament Pot Limit $100 - 2007-11-25 23:51:08 (ET)
Table: 4 (Real Money) Seat #7 is the dealer
Seat 2 - HEARTS_KING ($5445 in chips)
Seat 3 - JOFUS1 ($4710 in chips)
Seat 4 - FREE90FREE ($3395 in chips)
Seat 7 - JUDGERICHARD ($2890 in chips)
Seat 9 - FLAFISHY ($3675 in chips)
FLAFISHY - Posts small blind $50
HEARTS_KING - Posts big blind $100
*** POCKET CARDS ***
Dealt to FLAFISHY [6d 4h 8c Ah]
JOFUS1 - Folds
FREE90FREE - Folds
JUDGERICHARD - Folds
FLAFISHY - Calls $50
HEARTS_KING - Checks
*** FLOP *** [5h Ac 2h]
FLAFISHY - Bets $200
HEARTS_KING - Raises $800 to $800
FLAFISHY - Calls $600
*** TURN *** [5h Ac 2h]
FLAFISHY - Checks
HEARTS_KING - Bets $1800
FLAFISHY - All-In(Raise) $2775 to $2775
HEARTS_KING - Calls $975
*** RIVER *** [5h Ac 2h 6s] [10d]
*** SHOW DOWN ***
HEARTS_KING - Shows [5s 9d 3h 4s] (Straight, two to six)
FLAFISHY - Shows [6d 4h 8c Ah] (Two Pair, aces and sixes)
HEARTS_KING Collects $7350 from main pot
*** SUMMARY ***
Total Pot($7350)
Board [5h Ac 2h 6s 10d]
Seat 2: HEARTS_KING (big blind) won Total ($7350) HI$7350) with Straight, two to six [5s 9d 3h 4s - B:6s,B:5h,P:4s,P:3h,B:2h]
Seat 3: JOFUS1 Folded on the POCKET CARDS
Seat 4: FREE90FREE Folded on the POCKET CARDS
Seat 7: JUDGERICHARD (dealer) Folded on the POCKET CARDS
Seat 9: FLAFISHY (small blind) HI:lost with Two Pair, aces and sixes [6d 4h 8c Ah - P:Ah,B:Ac,B:6s,P:6d,B:10d]