Nothing about the 18 Kelvin lore talks about “mindless zombies”. It talks about the harsh working conditions at Clovis Bray and the murdering of employees due to distrust from Willa Bray. 1. 18 Kelvin refers to the Braytech facility in the Hellas Basin, not the one where SIVA was developed, and certainly not the Cosmodrome. 2. SIVA can only infect technology. It can infect guardian armor, but not human flesh. Unless the scientists were wearing some sort of technology on them, they can’t be controlled by SIVA.