Lets have a go at this.
Compare Windows 8.1 and Elite Dangerous do they have DRM?
Windows: Can be used on or off line at any time, installation must be validated either online or by phone, so internet is not needed, can only be installed on one machine/licence. Verdict has DRM.
Elite Dangerous: Can only be used online due to software limitations, installation does not need validation, and client can be installed on as many machines as you want.
Verdict Does not have DRM
Just trying to show that DRM had nothing to do with an internet connection
Good point, although I think the client may connect to FD servers for some kind of record keeping. I had this with some commercial engineering software. it needed to connect on install with a valid key. Officially, if you had one licence you should only have one instance running on one machine for one user at a time, but they were pretty relaxed about multiple installs (as the software often needed to be moved from machine to machine) or having one install at work and one at home to work at home. Where they clamped down was if a large company had one licence, yet many installs and many operators, they would check to see if you needed the multi licence setup. That software had DRM but it never got in the way or caused a problem offline.