I wouldn’t yet, at least not until it can be reproduced. At this point, I can’t, though I might not be taking the same steps as you. I tried two links, one with http and one without, and they were both nofollowed.
What version of bbPress are you using?
Is this just for a regular post in a regular forum, or is there special circumstances?
Is it for links that are discovered by bbPress, or the ones that are explicitly declared by the poster with A tags?