In reality, a "NAS" access protocol such as NFS or SMB or AFS will not have exactly the same access semantics as the native filesystem.
For instance, in unix, when you have a file that has a process reading / writing to it and you delete it, in a local filesystem, the link to that file vanishes but the inode won't be reclaimed until the process exits (and the link count goes to zero). At least in older implementations of NFS (and possibly newer ones, though I'm not sure), you'd wind up with that file getting renamed .nfs-#### and moved elsewhere, but not actually deleted. NFS best emulates the access patterns of a native unix filesystem.
SMB/CIFS, when mounted on a windows system, may appear exactly as if it is a local filesystem. I'm not sure, I don't have enough seat time on windows. Chances are, though, there are differences between an SMB mounted file and one on NTFS (and probably one that's fat32) that would be apparent if you're writing a weirdly low-level program.
You'll probably also see weird artifacts if you've mounted an NFS partition on windows or an SMB/CIFS share on unix.
Other more exotic things like AFS will also have weird behaviors relative to a local filesystem
So, in short, it depends on which NAS protocol you're using and which client you're using, and how closely you look.