Are you sure it's actually opening the email and not just giving you the contents in the preview screen?
When I go to view email in my bridge email, I see the email opened on the right hand side ... but the left hand side still shows that the email itself isn't selected. A simple delete erases everything without your having to physically "open" the email.
I assumed that this meant that the email wasn't really opened ... just previewed. I could be wrong on that ... wouldn't be the first time.