It's quite rare to have any kind of significant oil leak from the head gasket anywhere other than the front of the block between cylinder 3 and 4 where the pressurized oil channel goes up to the head. The only oil channels at the back of the block are oil drains at the corners. They are not pressurized and so to do anything other than weep, the gasket needs to be seriously damaged. Almost always, oil leaks at the back of the head are actually from the valve cover gasket not being seated correctly and just appear to be a head gasket issue.
That and the #1 cam cap needs a DAB of sealer under it.
just a short note of experience
i find with my aaz and previous 1.6td cam cover - using a rubber gasket and getting the surfaces as clean as possible made for a perfect seal. silicon sealant made it worse.
Yeah this is under the cam cap though, there's no gasket for it.