Recursively delete in an Object tree and retrieve deleted node

deletefunction.js

var Tree = Base.extend({
    constructor: function(tree) {
        this.tree = tree;
        this.count = this.count_nodes(0);
    },
    delete: function(node_id, tree){
        var that = this;
        if ( tree === undefined ) tree = that.tree;

        _.each(tree, function(node, i){
            if ( node_id == node._id ) {
                tree.remove(i);
                // IMA NEED TO RETURN node;
            }
            if ( node.is_dir )
                that.delete(node_id, node.tree);
        });
    }
}

document_tree = new Tree(t);
deleted_node = document_tree.delete(1);

documenTreeSyntax.js

var t = [
                {
                    is_dir : 0,
                    name   : 'file.txt',
                    _id    : 0
                },
                {
                    is_dir  : 1,
                    name    : 'foo',
                    _id     : 1,
                    tree    : [
                        {
                            is_dir : 0,
                            _id    : 2,
                            name   : 'leaf.txt'
                        }
                    ]
                },
                {
                    is_dir  : 1,
                    name    : 'bar',
                    _id     : 3,
                    tree    : [
                        {
                            is_dir: 0,
                            _id     : 4,
                            name   : 'leaf1.txt'
                        },
                        {
                            is_dir: 0,
                            _id     : 5,
                            name   : 'leaf2.txt'
                        },
                        {
                            is_dir  : 1,
                            name    : 'bar',
                            _id     : 6,
                            tree    : []
                        }
                    ]
                }
            ];