User blog comment:FairyRaven/Fairy Tail Chapter 377, 378: The Sky Dragon's Rage & Friends Forever, Review and Commentary/@comment-76.161.172.226-20140328211810

Carla saying that they'd die if Face exploded but they ended up surviving is easy to explain. Carla had an infinite amount of futures to attempt to search through, and a finite amount of time in which to do so. So she managed to find one future where they stopped Face, but died in the explosion, but ran out of time in which find one where they stopped it and lived.

The future Carla saw probably didn't include them spending a bunch of extra time on Wendy refusing to attempt to escape etc, and the extra time spent gave Doranbolt enough time to get there and save them.