Sneaky memory leak in Javascript

sneaky-leak.js

function makeBigObject() {
    var big = new Float64Array(10000000); // Allocate big object.
    return {
        one: function () { return big.length; }, // Has ref to big object.
        two: function () { return "hello"; } // Doesn't have ref to big object.
    };
}

function leak() {
    var l = makeBigObject();   // l has ref to big object via "one".
    delete l.one;       // Delete the "one" property. 
    return l;           // The big object is not supposed to be 
                        // reachable via l. However, l.two holds a
                        // ref to the big object via its closure
                        // scope.

}

var thing = [];
setTimeout(function doitagain() {
    thing.push(leak());     // big object allocated in makeBigObject() is
                            // supposed to be unreachable from thing.
    setTimeout(doitagain, 1000);
}, 1000);

// Watch your system die!