Ok, this is weird.
1. Even though the activatio failed, I see the BuddyPress admin section in the left-column of wp-admin (General Settings, Component Setup, etc.)
2. I have (2) BuddyPress plugins listed. One was showing as Active, the other as Deactivated. I deactivated the one that was showing as Active.
Now, I have (2) BuddyPress plugins listed, both deactivated. Not sure how this happened. What should I do?