If I see things are getting out of hand, or I'm not happy with the way things are being cooked - I'll always take over. I stay away from salads as a rule, especially if they've been sitting out all day. certain things I think you can trust - rice salads etc, which have all ingredients cooked, then chilled. is relatively safe - ditto with potato salad etc. I always make sure I've got some veggies cooking of the bbq, peppers, tomatoes, potatoes, sweetcorn, butternut squash etc... they usually all disappear before the salads do.
I avoid any salad which has any dressing on it, as it's a recipe for disaster. rice salads, potato salads and coleslaw are generally kept in the fridge until real food is ready so I think it's less of an issue.