Incorrect extracting of microdata

[alexkart]

html:

<div itemscope="itemscope" itemtype="http://schema.org/MusicAlbum">
    <h1 itemprop="name">Bat Out Of Hell II: Back Into Hell</h1>
    <div itemprop="artist" itemscope="itemscope" itemtype="http://schema.org/MusicGroup">
        <meta content="/artist/meat-loaf" itemprop="url"/>
        <meta content="Meat Loaf" itemprop="name"/>
    </div>
    <time dateTime="1993-01-01" itemprop="releaseDate"></time>
    <div itemprop="tracks" itemscope="itemscope" itemtype="http://schema.org/MusicRecording">
        <meta content="/artist/meat-loaf/album/bat-out-of-hell-ii-back-into-hell/track/id-do-anything-for-love-but-i-wont-do-that" itemprop="url"/>
        <meta content="I'd Do Anything For Love (But I Won't Do That)" itemprop="name"/>
        <meta content="Bat Out Of Hell II: Back Into Hell" itemprop="inAlbum"/>
        <meta content="PT718S" itemprop="duration"/>
        <span itemprop="audio" itemscope="itemscope">
            <meta content="en-US" itemprop="regionsAllowed"/>
        </span>
    </div>
</div>

library incorrectly extracts microdata:

[properties] => Array
                        (
                            [name] => Array
                                (
                                    [0] => 
        Bat Out Of Hell II: Back Into Hell

                                )

                            [artist] => Array
                                (
                                    [0] => 
        Bat Out Of Hell II: Back Into Hell

                                )

                            [releaseDate] => Array
                                (
                                    [0] => 1993-01-01
                                )

                            [tracks] => Array
                                (
                                    [0] => 1993-01-01
                                )

                        )

                    [type] => Array
                        (
                            [0] => http://schema.org/MusicAlbum
                        )                

correct structure should be:

[properties] => Array
                        (
                            [name] => Array
                                (
                                    [0] => 
        Bat Out Of Hell II: Back Into Hell

                                )

                            [artist] => Array
                                (
                                    [0] => stdClass Object
                                        (
                                            [properties] => Array
                                                (
                                                    [url] => Array
                                                        (
                                                            [0] => /artist/meat-loaf
                                                        )

                                                    [name] => Array
                                                        (
                                                            [0] => Meat Loaf
                                                        )

                                                )

                                            [type] => Array
                                                (
                                                    [0] => http://schema.org/MusicGroup
                                                )

                                        )

                                )

                            [releaseDate] => Array
                                (
                                    [0] => 1993-01-01
                                )

                            [tracks] => Array
                                (
                                    [0] => stdClass Object
                                        (
                                            [properties] => Array
                                                (
                                                    [url] => Array
                                                        (
                                                            [0] => /artist/meat-loaf/album/bat-out-of-hell-ii-back-into-hell/track/id-do-anything-for-love-but-i-wont-do-that
                                                        )

                                                    [name] => Array
                                                        (
                                                            [0] => I'd Do Anything For Love (But I Won't Do That)
                                                        )

                                                    [inAlbum] => Array
                                                        (
                                                            [0] => Bat Out Of Hell II: Back Into Hell
                                                        )

                                                    [duration] => Array
                                                        (
                                                            [0] => PT718S
                                                        )

                                                    [audio] => Array
                                                        (
                                                            [0] => stdClass Object
                                                                (
                                                                    [properties] => Array
                                                                        (
                                                                            [regionsAllowed] => Array
                                                                                (
                                                                                    [0] => en-US
                                                                                )

                                                                        )

                                                                )

                                                        )

                                                )

                                            [type] => Array
                                                (
                                                    [0] => http://schema.org/MusicRecording
                                                )

                                        )

                                )

                        )

                    [type] => Array
                        (
                            [0] => http://schema.org/MusicAlbum
                        )