Ellie, I'd have been exactly the same and there is nothing like a screaming baby to notch up the tension on what could have been a 'heated discussion' at another time.
I'm not one for controlled crying, at all, it feels too much like teaching them there is no point in crying cos mummy ain't coming.
DP and I had the same conversation the other day, he was worrying about me not getting any sleep and I've been getting up at least twice in the night to settle Alex, plus he has been waking twice before I've even got to bed so DP suggested just letting him cry.
I said if baby was old enough to understand (more like 12-18 months than 6 months, IMO) and I could actually say 'Look, it's bedtime, I love you and I'm only going downstairs but I'm not coming back up if you cry because it's bedtime' then I'd do it.
I've done it with both of mine when they were older, old enough to know what was going on, but I don't think 6 months is.
Grizzling, yes, fine, ignore, Alex sometimes grizzles because he's tired, it's a way of getting himself to sleep but once the tone changes, to actual crying I have to go in and get him.
FWIW, I honestly don't believe controlled crying would work on him, he doesn't settle when crying, he just gets worse and worse so I find it much easier to do PUPD (which is, in essence, the same message as CC is meant to be, non? Cry all you like but you are going to sleep, only difference is I'll settle you first?).
Would your DH read a book? Or internet print outs if you gave him them? I know some posters have recently posted studies that say CC can be harmful, not so sure on them myself but maybe it would help to sway DH? Also the Healthy Sleep Habits Happy Child book says to use PUPD so maybe that would help enforce your way a little? I find it helps to say 'We'll look this up together then cos I've read up on it a little and am rather impressed but I'm rubbish at explaining it, maybe if you have a look you can find a way where we don't leave ehr to cry, cos I just can't bear to hear it'