but you said it twice. anyway, that was in the dark ages for India. And, if not very much mistaken, didn't Union Carbide operate that place?
Union Carbide OWNED the plant, and provided some management. Far and away the majority of personnel were locals, including the guys who "pulled the wrong lever".
Union Carbide operated it, technically, but the place was on-hands managed by Indians. Not unlike Homer Simpson, a couple of engineers were "sleeping at the wheel" when the cyanide leak occurred and a chain reaction of miscommunication and the lack of emergency stopgaps created that disaster. Essentially, oversight was shoddy and a lot of people died for it.
India insisted (and achieved), both majority ownership and the final word on how the plant was to be run.