Maybe the FCOM was actually the design specification, i.e. how they wanted it to work, which however had significant differences from the final product? The ar

Maybe the FCOM was actually the design specification, i.e. how they wanted it to work, which however had significant differences from the final product? The article later points out that the many Direct Mode reversions probably have something to do with the Electronic Interface Units (EIUs) which are responsible for making sure the various off-the-shelf Western components (which were apparently not customized due to cost reasons) could talk to each other. So the only Russian-made (and thus technologically not so advanced) component in your design is also a single point of failure. What could go wrong?