If you use DigiMesh you are going to get the Origin MAC Address because this protocol doesn't return the internal hops.
So if you connect the two nodes, but both Origin and Source are the same it is right.
I dont understand why there are two different parameters for de mac origin address (macS and macO) if its imposible to make difference in multihop communication between the node that created the message and the node that fordwarded the message. It doesn't make sense. Is there any other way to know it?