http://openid.net/specs/oauth-v2-multiple-response-types-1_0.html#Combinations
Multiple response types are pure insanity, I can't see any point in "code token" (if you have the token, what's the point of the code? just to get the id_token?) or "code token id_token" (now the code is completely pointless) or "code id_token" (I need to hit /token for an access token anyway, so is the id_token there just for additional validation?)
I have written to the OpenID Connect mailing list and my email is "awaiting moderation". Frustrating.