Sorry, I don't really have time to put together a small project for it. The test is easy though - create a web project with a simple bit of javascript for a FileUpload. Create an MVC or Ajax web method, HttpPost, with the signarture like UploadFiles(List<HttpPostedFileBase> files). Then run it in your debugger. If you're using IIS Express, your site security is already set to Trusted, which enables the IE option to include the path.
Using the FileUpload control, if you select multiple files from your computer or a network share, there will be twice as many backslashes compared to picking one file.
It's quite possible a company is relying on the ability to upload paths using only IE, which allows that option.
Cheers