A few nights ago I was looking for something to watch while I went to sleep and I settled on an old movie called Conspiracy about the Wannsee Conference. There's only one record of what happened at the Wannsee Conference and it's obviously incomplete, so it's hard to say how accurately the movie portrayed what actually happened. But the basics were probably captured accurately.
Adolf Eichmann organized a meeting on the behalf of Reinhard Heydrich that included representatives from various ministries and branches of the military and police. The major decisions had already been made at the highest level, but there was some pretense of debate about what to do with the Jewish population in the occupied areas of the Third Reich.
Heydrich knew that there would be opposition to what he was going to propose so he walked them slowly up to the real news. He didn't just come out and say that they had built gas chambers and crematoriums. He walked them through all the logistical problems with trying to feed and house so many Jewish prisoners. He explained why their suggestions were impractical for one reason or another. And only after he'd gotten a lot of input and dismissed a lot of ideas did he and Eichmann spring the big news that there would be a highly mechanized program of complete annihilation.