Still makes no sense to me.
Their scope of investigation seems too limited, given the discovered span warping, lifting of abutment anchors, concerns that the original safety factor may now be less due to heavier locos using Lobato. Why not investigate ALL essential factors involved in rebuilding the structure?
Suppose it becomes necessary to install beefed-up, heavier, new components?
Two engineering outfits never checking existing foundations, if for no other reason than CYA seems absurd.
They've only got one chance to do it correctly and comprehensively before any construction starts.