Whereas initially, he was making payments to people daily...that seems to have changed significantly over the past week or so and now we aren't seeing payment daily, but every couple of days.
My suspicion level is growing with every passing day.
Based on the limited information available, I believe Btc-Arb's strategy has failed to return profits over most of the last week. Additionally, his system is probably not hedged, so he loses money when the bitcoin price goes down (but this reduces his debt more, as the debt is measured in terms of bitcoin).
I emailed him offering to exchange information shortly after his original post, but will email him again and offer to help more directly.
I can temporarily open my system and allow him to copy my investments manually. I am currently looking at an unusually high profit around $7 per bitcoin today, so he would have much higher yields.