Thank you for the answer, but I'm not a native english speaker. Are you sure that "financed" means buying on borrowed funds, but not borrowing funds?
Financed in a trading context just means trading on margin. The full context this time was
"financed long BTC/USD" so that can only mean borrowing USD to buy BTC.
To understand how Bitfinex is dealing with the fork you just need to think about who actually owns the coin at the moment it is forked. The owner gets the split token, not the borrower. USD is not being forked (don't give Janet Yellen ideas). If you have a margin BTC buy (are financed long BTC/USD) you borrowed USD to buy BTC. You bought the BTC, so own it and did not borrow it.