Blocked contact and multitasking menu iOS 8 What happens if I call or send a message to a contact I have blocked? 

Does that contact show up on the recent contacts multitasking menu?
Yes. Even messages to blocked contacts display that blocked contact in "Recent" in the app switcher. 

You can disable the "Recents" altogether if you would like. Go to Settings -> Mail, Contacts, and Calendar -> Show In App Switcher (under Contacts).