Many separate issues contributed to the disaster, including safety systems failing, malfunctioning equipment for grabbing bad gasses, storage tanks overflowing, and essential plant sections going down for maintenance without any redundancies. But if we have to point our finger at someone who needlessly made the whole thing worse, we'll single out Shakil Qureshi.
Shakil Qureshi was the supervisor devoted to methyl isocyanate. At 11:30pm, workers noticed a gas leak when their eyes started watering. They wore no eye protection, presumably so their eyes could function as effective methyl isocyanate detectors. An operator named V. N. Singh then discovered the dripping source of the leak (the methyl isocyanate was stored as liquid and only became gas after it escaped its tank) and informed Qureshi at 11:45. Qureshi said that he would address the issue ... would address it after he finished his tea.
He took just under an hour to finish that tea. That was enough time for the leak to progress significantly. Afterward, Qureshi said that when he'd heard the warning, he'd thought Singh meant a water leak, not a gas leak, which explains why he thought it was no big deal. But when your job title is officially "methyl isocyanate supervisor," you should be primed to think "gas leak" at the slightest suggestion. Like, we wouldn't be very sympathetic if the core supervisor at Chernobyl said, "Oh, a core meltdown? I assumed they were reporting a Twitter meltdown!"
Speaking of Chernobyl, the Bhopal disaster is absolutely ripe for a Chernobyl-style miniseries. And now that we look it up, it seems there was a Bhopal movie made within the past decade. It was Indian-produced but starred Martin Sheen, as the Union Carbine CEO who was charged with manslaughter and died a fugitive a month before the movie came out. Apparently, the movie had an worldwide box office take of ... $12,628. See, Bhopal: A Prayer for Rain never saw wide release (unlike the methyl isocyanate).