Okay when you are playing Winter Contingency you come across a group of Zealot class Elites, one of which barges past you and escapes… Emile said that the Elite got past time but Kat close massive bulk head like doors that there is surely no possible way for it to power through, so how did it manage its escape? Is there another door I am unaware of but even then if there is why did Emile say it got past him considering he was in front of the huge doors of the base?

They escaped through a different set of doors. The ones Kat closed lead to the outside where the Falcon drops you off. The doors the Elites went through lead you deeper into the base.