Chrono wouldn't be in a party mood until he gets his gear problem sorted out, which in-game will take no less than 15 minutes.
Random thoughts and responses follow:
Also we just killed a guy, so that's not really something to party over.
Also I just realized Lothmar said he's the only one with a confirmed kill, but that's true if you only count non-skellies
Also I'm not sure what Raigne is upset about (again) - Chrono most likely saw Lady digging through the corpse (twice?) and the two girls passing jewelry around (twice?). It's only natural to ask.