Yeah, to me the delivery of the story went off the rails at this point.
Clem starts crying, Lee pulls this limp-armed 'reach out' attempt, then just walks away, conveniently places her walkie-talkie out in the open and sits on the sofa staring at a wall while she's sobbing until he falls asleep? Seriously? After all they've been through together, Lee just turns into a robot?
I was disappointed. They could have completed that scene with all the necessary plot elements in a far more meaningful way. I suspect they were rushing to meet a deadline. I can't imagine why else they'd completely drop their otherwise flawless standards in delivering a great narrative. 'Shame it had to be at such a crucial moment in the story.