Why is Ronsel lying in the wagon at the end of Mudbound?

According to Wikipedia, he survives:

Pappy, who had previously seen Ronsel riding in the front seat with Jamie, finds the photograph of the white woman and mixed-race child on the front seat of the truck. Ronsel, out searching for the missing photo, is picked up by Pappy and other members of the Ku Klux Klan and brutally beaten. Pappy then fetches Jamie and forces him to witness the "trial" prior to the lynching of Ronsel. Jamie tries to fight off the men, but is beaten and restrained, and Pappy forces him to choose Ronsel's punishment for the "crime" of miscegenation, documented by his photo: to lose his eyes, tongue or testicles. If Jamie refuses to choose, Ronsel will be murdered. Jamie is forced to watch the tongue mutilation, and Ronsel is strung up and left for his family to discover.

[...]

The film returns to the opening scene, and eventually Hap agrees to help but refuses to allow his sons to assist in lowering Pappy's coffin. Jamie gives the photo of Ronsel's son to Florence to pass on to Ronsel.

[...] The Jacksons eventually settle on a farm of their own. A mute Ronsel makes his way back to Europe where he reunites with his girlfriend and son.

After watching the relevant scenes, it is clear that Ronsel is still alive: you see his mother care for him, etc.. He is likely hidden on the cart to be "smuggled" out of town, and the rest of the movie is "what has happened next".

The director talked to Film School Rejects about this ending, because it is different from the book:

Virgil Williams: The ending, of course, was different in the movie than the book and that was a contribution that I made that and that I’m most proud of.

Andrew Karpan: Tell me about your decision to change that. It really changes the tone of the movie.

Virgil Williams: What’s just more important in a movie than a novel is to leave people in a state of feeling; for me, a film is really made in the language of emotion. And in that book, Hillary [Jordan], she was upset when I told her I was going to change her ending, just alludes to the possibility of what Ronsel could potentially be and where he could potentially go. And I didn’t think that was a satisfying enough ending.

And part of that is that I’m a minority, and, quite frankly, there are too many fatherless black children in the world. For Russel to truly occupy the space of a hero, he needed to go get his son. It is the very reason he got his tongue cut out and if he didn’t fulfill that relationship, it would have felt very non-cinematic and, quite frankly, not satisfying at all. And, after all that pure truth in the movie, after all that searing idea of America, you really need to end on a hopeful note. Mudbound, I hope, shows us who we were and, in doing that, it shows us who we are and on that hopeful note will inform who we choose to be.