.fin() without a .then() breaks ordering

expected.txt

then1
then2
fin1
fin2
fin3

output.txt

then1
then2
fin3
fin1
fin2

sample.js

var Q = require("q");

var promise = Q.resolve("ok");

promise
	.then(function(v){
		console.log("then1");
	})
	.fin(function(){
		console.log("fin1");
	})
	.end();

promise
	.then(function(v){
		console.log("then2");
	})
	.fin(function(){
		console.log("fin2");
	})
	.end();


promise
	.fin(function(){
		console.log("fin3");
	})
	.end();