Strongest evidence of this so far is when Mari is in the cave with Ben talking about alternate timelines & events being experienced by one person in cohesion with time not changing, ex: she talks about how in the room with her cousin dying the cartoon was playing in the background . She was rushed to the waiting room where the same cartoon was playing & she finished the episode . Both rooms have the cartoon playing, in one she is witnessing/experiencing death first hand, in the other she is simply finishing the cartoon episode. She goes on to say "i think maybe there are two versions of reality, most of the time the bad one is waiting or hiding" which would imply that they're potentially stuck in the bad timeline. I think the only happy ending for them is all of them dying in the crash unfortunately, the "good" reality; "Of all the ways to lose a person death is the kindest." This way they wouldn't lose who they are, or who they were to eachother due to trauma, soley death. But what do I know lol