Bjørn Lomborg's assistant emailed me this morning to confirm that Mr. Lomborg no longer wished to have an entry on the Heartland Institute expert list:
Thank you for your email pointing out to the affiliation problem.
As Lomborg is not affiliated with the Heartland Institute, we asked them to take Lomborg off from their list.
On behalf of Bjorn Lomborg
Some background here and here, if you haven't been following.