1) They have to explain to the credit card chargeback authority what a bitcoin is and why the entry in the block chain means they actually sent the coins.

2) Nothing to stop the Bitcoin buyer from just saying "I didn't do it" (Which is 'friendly fraud' in the article).

From my experience, reversing a chargeback is only possible in a minimum of cases when sending physical items, and even harder for digital goods that you can't just send again (Bitcoins vs an Ebook).