Look for this line in your transformation:
<%# BlogFunctions.GetBlogCommentsCount(Eval("DocumentID"),Eval("NodeAliasPath")) %> comments
If you have not made anything custom, it would be CMS.BlogPost.Default
Sorry I re-read your question and realized you are probably looking for how to react to having comments disabled on the actual CMS.Blog page. Assuming your NodeAliasPath to the blog is at "/Blog" it would be some boolean check that looks at the BlogOpenCommentsFor property.
Documents["/Blog"].BlogOpenCommentsFor == 0
0 == Disabled
-1 == Always
N == number of days comments are allowed for.