Yeah my knowledge of 767 systems are nonexistent. I know in pretty much all the aircraft I fly if the primary hydraulic system that drives gear extension/retraction fails there is going to be some sort of abnormal gear extension procedure (such as gravity drop, pumping the gear down, or running it off of a separate system driven by a DC pump). I should have guessed larger aircraft would have their primary gear extension driven by multiple hydraulic systems.
If I read it right the failure of the electric motors to release the landing gear uplocks was a completely independent failure (caused by popped CBs) from the hydraulic system failure (which was not caused by the popped CBs that caused the uplock failure)?