I find these kind of statements funny, but they are true:
This is the mentalitet that Epic has. If you read the FAQ frequently asked questions, it basically says you can copy modify sell delete make your own engine using the unreal code… or do what ever you want with UnrealEngine sourcecode, only thing you need to remember is that after you have made a million bucks profit, you start to pay Epic 5% from the profits after the first million.
And note that the million is per project, it is not the total of all projects.
a project that makes only 900k$ is royalty free, if your other game makes 1.1million then that game is royalty 5%.