I think Unreal wins there because the engine is open source and modifiable whereas Unity's is not.
Create Epic account, link to Github, receive access to UE4 repository. Probably can be revoked easily.
Or get it via launcher, after log in into your account.
Also, you cannot post online more than 30 lines of engine code (forums, stackoverflow,etc).
I'm not a lawyer.
Edit: launcher part.
Open source means you can use it and redistribute it freely.