gistfile1.js

var callbacks = [1, 2, 3].map(function (x) {
	return function () {
		console.log(x);
	};
});

var wrong_invoke = function () {
	callbacks.forEach(function (callback) {
		setTimeout(callback, 0);
	});
};

var correct_invoke = function () {
	setTimeout(function () {
		callbacks.forEach(function (callback) {
			callback();
		});
	}, 0);
};

@rtm if there's a spec, a library's behaviour can be:

1. conformant
2. non-conformant
3. undefined (by the spec)

In this case, the spec does define the correct behaviour: executing the callbacks in the order they were registered.
This leaves only two options, so I would argue that this is a black and white situation.