Manga News: Check out these new manga (5/11/15 - 5/17/15).
New Forums: Visit the new forums for Boku no Hero Academia!
Forum News: Cast your votes to determine the best parent in the Anime Showdown.
It will be near impossible that the author cared so much about this story and than forgot something FUNDAMENTAL like how Berthold could escape after the re-transformation.
He highlighted this topic in a recent chapter too (can't remember which one) so I'm pretty confident there will be not a plothole about this ^^