I think Dave is OK with all of the Jamie stuff... he was pitching in quite a bit anyway.
I think it's the L word that has really thrown him and made him think about what is happening and how this will work outside. He made a weird comment last night - pretty much the only thing he said - about you can get through the experiment and do everything right and still not fall in love (unless I misheard!) And it's true and it's why MAFS (and life!) has always bothered me....you can be great on paper and you can have experts coaching you about how to make the relationship better...but it can't give you that thing that makes it all fall into place.
Also I think Jamie is great anyway and she is learning loads about her behaviour, good and bad, on here. Her apology to Carina was so genuine last night and I think even she is realising that actually even if she comes out of this without a partner, she's still benefited massively from being on MAFS.