i noticed ppl from certain groups tend to do this more than others
Cough in your elbow as well. It makes a huge difference (mythbusters proved it...). Anytime I see someone cough into their hand my insides die.
I hope you stepped up to the challenge and asked/told them to cover their mouths. You'd be doing everyone, including both them and you (next time they cough) a favour.
My roommate ALWAYS coughs into his hands, wipes them briefly on his pants, and then continues touching fucking everything without ever washing his hands. He won't listen to me when I demand otherwise and thinks I'm just being anal about things. I attribute almost all of my colds to him because his immune system is way better than mine.