I'd say yes.
The definition of a sandwich is "an item of food consisting of two pieces of bread with meat, cheese, or other filling between them, eaten as a light meal."
A hotdog bun technically is two pieces of bread barely put together. However, it looks like it is only one piece of bread.
What if we were to put a hotdog sideways?
That hotdog really resembles your typical sandwich here. A piece of bread on top, and bottom with the meat in the middle.
I'm curious, what is your guys's opinion on this? Does this dish really belong in the sandwich category of food?