Definitely agree, once I got my helmet and found how to hide it I was pretty sure I'd have problems hiding my companions.
My surprise is that as this is a Bioware game that the helmet doesn't automatically hide whenever you enter a conversation, that was standard practice in KOTOR I think, and definitely the case in Mass Effect 1 and Dragon Age Origins. Thinking about it though I'm not sure if the feature remained in ME2 and DA2.
Definitely don't want Corso running around with the starting smuggler helmet, it's an ugly looking scrum cap from rugby