Pie Animated update issue

First update looks weird. Problem only occurs when plotOptions.pie.animation is false

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>

<div id="container" style="height: 400px"></div>
<button id="button">Update first slice</button>

JavaScript

$(function() {
    
    var chart = new Highcharts.Chart({
        chart: {
            renderTo: 'container',
            //Problem only occurs on pie
            type: 'line',
            animation: {
                duration: 1000
            }
        },
        xAxis: {},
        plotOptions: {
            series: {
                animation: { duration : 1000 } //Problem only occurs when plotOptions animation:false
            }
        },

        series: [{
            data: [29.9, 106.4, 20]}]
    });

    // button handler
    var y = 30;
    $('#button').click(function() {
        chart.series[0].data[0].update(y += 10);
        //This gives the same problem:
        //chart.series[0].data[0].update(y += 10, false);
        //chart.series[0].data[2].update(y / 2, false);
        //chart.redraw();
    });
});