node-mongodb-native improper behavior with w:2 for insert and findAndModify

safeErrors.js

// Run this with 'nodeunit safeErrors.js'
//
// Create a replica set with only 1 replica up and do an insert with w:2 and findAndModify
// with w:2. Note that the insert returns right away successfully, even though the data 
// was not replicated. The findAndModify has different behavior. It actually times out 
// but still returns success!

var mongo = require('mongodb'),
    Db = mongo.Db,
    Server = mongo.Server,
    ReplSetServers = mongo.ReplSetServers
;
var inspect = require('util').inspect;

exports['hang on findAndModify'] = function(test) {
    var replSet = new ReplSetServers([
        new Server('s1', 27017)
    ], {rs_name: 'rs'});

    var db = new Db('test', replSet);

    db.open(function(err, client) {
        if (err) console.log(err);
        test.ok(!err);

        client.dropDatabase(function(err) {
            test.ok(!err);

            var collection = new mongo.Collection(client, 'contests');
            var beforeInsert = new Date().getTime();
            collection.insert({play_cursor: 101, plays: [{
                timestamp: new Date(),
        	active: false,
                uuid: "44acfea5-d321-4e43-bb85-61be896a9ccb"
            }]}, {safe: {w:2, wtimeout: 5000}}, function(err, docs) {
                var afterInsert = new Date().getTime();
                var diff = afterInsert-beforeInsert;
                console.log("insert time = "+diff);
                var contest = docs[0];
        	var play = contest.plays[0];
                var beforeFindAndModify = new Date().getTime();
                collection.findAndModify(
                    {_id: contest._id, 'plays.uuid': play.uuid},
                    [],
                    {$set : {'plays.$.active': true, 'plays.$.cursor': contest.play_cursor}},
                    {new: true,  fields: {plays: 0, results: 0}, safe: {w:2, wtimeout: 5000}},
                    function(err, contest) {
                        var afterFindAndModify = new Date().getTime();
                        var diff = afterFindAndModify - beforeFindAndModify;
                        console.log("findAndModify time = "+diff);
                        db.close();
                        test.done();
                    }
                );
            });
        });
    });
};