As I do this stuff for a living I tend to disagree with the "rust" causing the failure. It maybe a small contributor as material loss but the failure mode based on just the photos is binding and overload. A bit hard to say for sure without examining at the actual fracture faces but I can confidently say its not a corrosion issue in this fracture. The bushing carrier tubes (at the fractures) are still too thick to call it corrosion metal loss. In the first photo, you can see a portion of the welded region completely shearing off the tube. JMHO base on photos posted.
