Looks like the back car definitely made it to the station, found this tweet.
I think the translation of the news story from French made it difficult to understand. Sounds like when the train dropped from the first lift hill, the back car rolled back into the station while the rest of the train continued towards the 2nd lift hill, but the e-stop engaged causing it to stop at the bottom of the 2nd lift, after the loop. You can see from the images it's not actually valleyed--it's quite a ways up the 2nd lift when the e-stop brakes engaged.
