There's an entire world outside of the Internet, so it doesn't make sense to me that the lawyers would decide that the Irwins needed to go on national TV to fix their image because people on a forum think they are guilty. TBH, I think most people completely forgot who Deborah and Jeremy are, or don't know who they are in the first place.
DB constantly references the theories, rumors, & discussions that are online. She or someone close to her keeps her informed of what the rumor mills are churning out on the internet.