The word how automatically suggests you to give some sort of reasoning, therefore being a question.
normally having how at the start of a sentence denotes a question and having it in the middle denotes a statement
How nice of you to give us this false information.
Don't sleep during class dumbass
I think he just dozed off, because he probably had school early.
Yaya, but mine is at the beginning and it's not a question, see: