Environmental Impact Assessments (EIAs) are vital exercises for evaluating the effects of proposed activities on the environment and human well-being. In many countries, including India, they often suffer from incomplete biodiversity information and data manipulation. These issues are compounded by a lack of scientific rigor, independent review, and sufficient public participation—problems that are especially critical in biodiversity hotspots. This paper examines a ‘Cumulative Impact Assessment’ by the Wildlife Institute of India (WII) published in 2025 for the double-tracking of an existing railway line passing through Bhagwan Mahavir Wildlife Sanctuary and National Park in Goa and Kali Tiger Reserve in Karnataka—both part of the Western Ghats, a global biodiversity hotspot. The WII EIA was compared with the Indian Institute of Science’s (IISc) ‘Biodiversity and Environmental Assessment’ study that was previously prepared in 2017 for the same project. It was found that while the new EIA by WII addressed some of the gaps of the previous EIA, it failed to make a comprehensive assessment of projected biodiversity loss, leaving out some important taxonomic groups such as freshwater fish, insects, arachnids, and fungi, and failing to address its own study objectives, such as identifying critical wildlife habitats. It also neglected social impacts, despite widespread public opposition in Goa. The WII EIA fundamentally functions as an incomplete species inventory with mitigation measures, implying a conditional approval for the railway project. It does not assess loss in landscape-level connectivity, fragmentation of wildlife corridors, changes in human–wildlife interactions, and impacts on human health. This comprehensive review supports the call put forth by other scientists globally for the need for rigorous, independent peer reviews of EIAs, especially for projects with severe ecological and socio-economic consequences, planned in biodiverse and irreplaceable landscapes.