i concur.
as an amateur framebuilder, i can tell you that those lugs are also stamped, not cast. stamped=formed out of a sheet of metal, and welded along the seam, which somet yields an non-uniform lug inside surface, which brass won't flow nicely through. as a repair i wouldn't recommend it unless you had a friend willing to gain some experience repairing it.
as an aside, this failure has little to nothing to do with the tubing of the bike. it's a matter of poor lug stamping/finishing, and/or poor brass penetration.
dave