It sounds like you did really well over a difficult weekend. Well done you! I wouldn't beat yourself up about not flirting with H. I think it can be difficult at the best of times, but especially under the stress of sorting out moving things it'd be impossible....
On the other hand, I'd also say not to be afraid of flirting. If you just do the physical things, like eye contact or a light touch on the arm etc a man will pick up on it if he wants to, but isn't so obvious that he would have to say something to you about it, or run away from you as a result. Don't be scared to try (I want to say that to you too T!). Keep experimenting!
I'm so excited that you and H spent so much time together and I love that you were singing together during the ride. I think that will remind him of your connection and the fun you had together. He'll definitely be thinking of it and remembering!