D.Child have his ballad version of Livin. He said in on of his last interview that it was his song which he finally made with Bon Jovi. If I will find that one I'll put here.

But I use them both because important thing is who started doing song/demo. It's important on this topic to divide on two things -> someone made demo and send to many artist or someone write song working only with Bon Jovi. It's not importand who did that ghost writers or songwriters.
They used chorus from D.Child song. They based on previous D.Child work.
Melody was bought (according to story) but rest was done by Bon Jovi. Makeing it sound like rip-of The Beatles song is another story. We have here ghost writers and little rip off.
Where's problem? Company pay only if band use that demo and relase. Sia take money only if someone take her work. Noone take her demos from last album (or she decided to keep them) so she relased it as a album.

Sound and was written at the same point of time. And like I said in that topic we know that record company give their demos to many artist at the same time. You probably won't ever know if that's true. Only if someone tell that but probably they can't do that. But there's too many similarities to say it's can't be true..

Like I said before. They could use the same demo song and made their own song. Look at Avicii/Guetta songs.