My guess, and it is just from what i've read on here, so it's a pretty wild guess...
He's bought out his contract (with funds from us possibly) and Mallorca are left in a shitty position as they still owe his original Argentinian club some kind of payment. So Mallorca are going to try and get us to pay that as the player is no longer theirs. I'd say Mallorca are in a weak position myself. We will see.
This Webster m'larkey needs looking at though, wide open for abuse and misuse.