uhm I dont see anything wrong in the guy not seeing her off, neither do I see a big deal with the goodbye hug and kiss, cos those things are not programmed, they come with mood, and if the guy is not in a good mood for it, then he likely won't do it.

Women are emotional beings. If you’ve been conscious to maintain a habit with a woman every single time, it sticks. That has become her norm. Especially over something this basic and effortless. The day you change that habit, you are sending her a wrong signal.
I think a simple hug, “take care” and “I would have walked you out but I don’t feel strong enough” would have shown more care than just opening the door, letting her out and going back to watch Netflix.

also she told you the guy is having stressful time with his work so his mood was probably off

She assumed. She doesn’t know for sure. Said he seemed to be having a rough day at work.

If their relationship was defined, she would probably tell him how that pissed her off, and he would apologize

Exactly. This is why I love defined relationships. I get to be able to communicate with my partner without holding back and address issues no matter how great or small rather than internalize stuffs like my girl is doing.

Anyways, I trust they’ll be okay. It doesn’t seem like a deep issue.

but that does not mean he won't do it again.

Why do you sound so sure?😅 You don’t like peace, eh?