Loop freeze bug

<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8' />
    <title></title>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
    <script src='https://api.tiles.mapbox.com/mapbox-gl-js/v0.32.1/mapbox-gl.js'></script>
    <link href='https://api.tiles.mapbox.com/mapbox-gl-js/v0.32.1/mapbox-gl.css' rel='stylesheet' />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.4.0/d3.min.js"></script>
    <style>
        body { margin:0; padding:0; }
        #map { position:absolute; top:0; bottom:0; width:100%; }
    </style>
</head>
<body>

<div id='map'></div>
<script>
    /* jshint esnext:true */
var flightPath = {
  "type": "FeatureCollection",
  "features": [
    /*{
      "type": "Feature",
      "properties": {
        "marker-color": "#7e7e7e",
        "marker-size": "medium",
        "marker-symbol": "",
        "bearing": 350
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          144.96288299560547,
          -37.82171764783965
        ]
      }
    },*/
    {
      "type": "Feature",
      "properties": {
        "bearing": 270
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          144.9785041809082,
          -37.808359917423594
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "marker-color": "#7e7e7e",
        "marker-size": "medium",
        "marker-symbol": "",
        "bearing": 180
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          144.95558738708496,
          -37.8057830213145
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "marker-color": "#7e7e7e",
        "marker-size": "medium",
        "marker-symbol": "",
        "bearing": 90
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          144.94434356689453,
          -37.81649689372308
        ]
      }
    }
  ]
}

d3.json('https://api.mapbox.com/styles/v1/gisfeedback/ciwmwq2gb00fa2ppabho4z39c?fresh=true&access_token=pk.eyJ1IjoiZ2lzZmVlZGJhY2siLCJhIjoiY2l2eDJndmtjMDFkeTJvcHM4YTNheXZtNyJ9.-HNJNch_WwLIAifPgzW2Ig&_=1481601754051', function(style) {

var allbuildings = {
      "layout": {
        "visibility": "visible"
      },
      "type": "fill-extrusion",
      "source": "composite",
      "id": "mapbase-buildingfootprints-bwuw1f",
      "paint": {
        'fill-extrusion-opacity': 0.8,
        'fill-extrusion-color': 'grey',
        'fill-extrusion-height': {
            type: 'identity',
            property: 'HEIGHT'
        }
      },
      "source-layer": "MAPBASE_BuildingFootprints-bwuw1f"
    };

style.layers[style.layers.length-2] = allbuildings;

/*var dambuildings = {
      "layout": {
        "visibility": "visible"
      },
      "type": "fill-extrusion",
      "source": "composite",
      "id": "dam-footprints",
      "paint": {
        'fill-extrusion-opacity': 0.9,
         "fill-extrusion-color": {
            "property": "shape_type",
            "type": "categorical",
            "stops": [
                ["podium", "hsl(220,80%, 40%)"],
                ["tower", "hsl(220,80%, 60%)"],
                ["tower_pod", "hsl(220,80%, 60%)"]
            ]
        },
        'fill-extrusion-height': {
            type: 'identity',
            property: 'ovlhgt_ahd'
        }
      },
      "source-layer": "developmentfootprints-aehdyj"
     };
    style.layers[style.layers.length-1] = dambuildings;*/
    style.layers[style.layers.length-1] = undefined;
    style.layers.length = style.layers.length - 1;

mapboxgl.accessToken = 'pk.eyJ1IjoiZ2lzZmVlZGJhY2siLCJhIjoiY2l2eDJndmtjMDFkeTJvcHM4YTNheXZtNyJ9.-HNJNch_WwLIAifPgzW2Ig';
    var map = new mapboxgl.Map({
        container: 'map', // container id
        style: style,//'mapbox://styles/gisfeedback/ciwmwq2gb00fa2ppabho4z39c/', //stylesheet location
        center: [144.97, -37.82], // starting position
        zoom: 15,
        minZoom: 14,
        pitch: 45
    });

var posNo = 0;

var positions = flightPath.features.map(feature => ({
        center: feature.geometry.coordinates,
        zoom: 15,
        bearing: feature.properties.bearing                                                        
    }));
    /*var positions = [
        { center: [144.96, -37.8], zoom: 15, bearing: 10},
        { center: [144.98, -37.84], zoom: 15, bearing: 160, pitch: 10},
        { center: [144.995, -37.825], zoom: 15, bearing: -90},
        { center: [144.97, -37.82], zoom: 15, bearing: 140}

];*/
    function moveCamera() {
        var pos = positions[posNo];
        posNo = (posNo + 1) % positions.length;
        pos.speed = 0.1;
        pos.curve = 1.1;
        if (pos.pitch === undefined) pos.pitch = 45;
        map.flyTo(pos);
    }
    map.on('moveend', _ => setTimeout(moveCamera, 500));
    map.on('load', _ => setTimeout(moveCamera, 500));

});

</script>

</body>
</html>

https://api.tiles.mapbox.com/mapbox-gl-js/v0.32.1/mapbox-gl.js

https://cdnjs.cloudflare.com/ajax/libs/d3/4.4.0/d3.min.js