When you committed my most recent patch (http://reviews.review-board.org/r/352/) you made a slight change that introduced a bug. Specifically, ReviewRequest#publish no longer returns a ReviewRequest, which was expected in one place.

Since there's no longer actually any reason to return a review request, I fixed it in the caller.

Try to submit a review request from the web UI. You'll see a 500 error without this patch.