gistfile1.js

From this:  (seems logical to me)
 onAppSaveArticle : function(article) {
        var savedArticles = this.getSavedArticles(),
            model         = savedArticles.getModel(),
            foundRecord   = savedArticles.find('id', article.id),
            record;

        if (foundRecord == -1) {
            record = new model(article);
            savedArticles.add(record);
            savedArticles.sync();
        }
    },

to this:
 onAppSaveArticle : function(article) {
        var savedArticles = this.getSavedArticles(),
            model         = savedArticles.getModel(),
            reader        = model.getProxy().getReader(),
            foundRecord   = savedArticles.find('articleId', article.id),
            cleanData;

        ! reader.getModel() && reader.setModel(model);

        if (foundRecord == -1) {
            cleanData = reader.extractData(article)[0].data;

            savedArticles.add(new model(cleanData));
            savedArticles.sync();
        }
    },