If there was a fuel leak, it would have had to have been small. They were 2 hours out when they turned back and (it appears) fuel did not show as a problem. Whilst evaluating how much to dump, they would have checked levels closely and a leak should have shown up.
So, again, the question might be: If it's only an oil leak, should you have RFF waiting for you ... Whatever the current thinking is, it will now change, at least at SQ.