"When is it OK to take a wrong/bad action in order to prevent some really wrong/bad event?"

"How wrong was this action?"

"How bad does the event have to be to justify the wrong action?"

"Who is responsible for making the judgment call?"

"If that party shirks, does it fall to anyone next?"

"Who is morally accountable for the bad event given that it could be avoided via certain actions?"

The scientific consensus you refer to gives important and helpful facts that inform this discussion by characterizing the bad event in detail. But the scientific facts cannot answer the foregoing questions, as you hope, because it provides no insight on any of the other facets. That's why there's debate and discussion rather than an open and shut case.