Node Type in Views Template
I believe you are using the wrong template in order to access the relevant information. As your comment states your view template is for the entire View, and as you say it looks through the entire document and will always find the content type if any content of that type is present.

Since you are trying to affect a single field, you should look at other template suggestions for fields only in order to process the fields individually instead of trying to do it at the whole View stage.