Quite an impressive set of snapshots. It really goes to show no matter what, you must always keep in mind the wild nature of these animals. This was probably something they had done before without problems, and will probably do again. However, the comment about releasing on a bridge is a good one. It limits the escape routes the bear had. I wouldn't be surprised if the cage is modified to allow remote release.
Note to self: Make sure when bear releasing that I am wearing a hat that I don't mind losing.