Either BFL cashing out some coin, or they suckered some poor fool. Or maybe, all of BFL's so called regular customs just got the shaft big time as a big order like that is going to get special treatment at the cost of smaller orders.
I'm sure BFL is liquidating some of the massive bitcoins they've mined... Think about it - BTC is hovering at a premium right now. Its what I would do.
But why pay Bitpay the commission ?
They could sell the mined coins on exchange and nobody would notice