You guys gave him a bunch of coins. He took it. Every so often he pops back in to throw some pennies back to you guys and you guys sit here and take it.
The alternative is the expense of a protracted legal action against the primaries involved with BTC-Arbs, in a foreign country, with no certainty of receiving anything in return financially. Although many people are aware of the identities of those who ran BTC-Arbs, the incentive to pursue legal satisfaction isn't there if they continue to demonstrate an intent to refund everyone...even if it takes a long time.
So what are we going to do? Wind them up with legal action that stops all funds from being returned to people? Or just wait it out and let them try to make restitution. Because he's still here six months later, paying people back...it may be slow, but it's still happening. As far as whether or not the repayment is the result of arbitrage, or whether he took a second job to pay people back...I don't much care.