Need help gen 2 leak oil after repair

Need help.
I took my 5.7 tundra to get a coolant leak fixed on the heat echanger on valley of engine. Mecanic replaced and fixed it. But when i took truck home is was leaking motor oil down the rear engine driver side. Took back to him he took intake manifor againg out and checked and no oil was on top on valley. He replaced pcv valve and secondary air pump behind manifold. Put all bavk together and took home. Still leaks oil down same place. He look at it again and says that oil is coming down a small pipe/tube that sits on driver side on rear block. Right by where goes in block and has a bolt and a rivet.

So my truck was fine before. Does oil goes thru that pipe or is gases. Because the other end of that pipe is connected to the vapor separator(a blavk plastic pievlce that goes on top of heat echanger.

Someone at overstock parts toyota lakeland told me that is some is stuck on the breather where gases go it can cause leak oil. But the problem is truck did not leak at all before took for coolant service