The man is STUCK in a TRUCK with this woman. What do you expect him to do? Do you think the next 24 hours would be tolerable if he talks to you in front of her??? She'd make his life HECK!!! He's just trying to keep his head down until he can drop her off.
There are a lot of things to be mad at your H about, but this isn't one of them! And by getting all po'd about it, you start to look like "crazy Emily" and he will start to feel like there's no use coming home, you'll just scream at him anyway.
Once he's at your place, professing his love for you and willingness to do whatever it takes, you can always ask him to call OW in front of you and tell her it's over. But really, right now you're not being reasonable about the tough spot he's put himself in. Continue to look good in comparison to OW by being calm.