The history of the Strait of Messina Bridge project has been quite complex. 
The project was shelved in 2012 by the Monti government (see also What are the main milestones in the history of the Strait of Messina Bridge?) not due to “serious shortcomings in the final design” but rather because of financial considerations related to the well-known international economic situation at the time. No objections were ever raised regarding the quality of the design prepared by the General Contractor. As is well known, Eurolink’s Final Design, comprising approximately 10,000 drafts, successfully underwent extensive review, scrutiny, and validation processes.