Well, if you look at EK's credits
, you see that there's nothing left to be explained.
Also, if you actually look at Flare and EK, you'll see that only early EK parts use free (or open source assets), and with time, as David had more money to put into development, there's original EK graphic, which he shared with Clint (Flare).
And, this is only graphic, as all coding, writing, etc. is original David's work, without any relation to Flare.
I understand that today people when they see images think it is everything, without anything behind it, but image is just image so to say, and coding, story, writing, devise world (or game) rules, spells, etc. etc... is different story.
If someone don't know something about copyright and credits on EK's part, it is more of a problem with this particular someone, not that some facts are hidden, or left out unexplained, or something similar.
Simply said, people don't explore EK's credits and think that there's something shady going on, no matter how far from truth that is.