I have a php file that is working outside wordpress's plugin and template system, and I am calling get_post to get the post's content. Does it count as a post view?
WordPress doesn't count post views. So no. Nothing counts as a post view.
If you're using a plugin or service that counts post views, then it would depend on that plugin or service, and how it measures views. You'd need to ask its author, but I feel safe saying that none of them would use
get_post() to count views.