The decision has also drawn heat from The National MS Society, who told FOX411's Pop Tarts column that they were "sorry that Jack's participation in 'Stars and Stripes' did not work out." 

"For those with MS, or any other disability, there are protections in place under the Americans With Disabilities Act should they find that their rights have not been respected," their rep said.

NBC producer David Hurwitz denied the allegations, stating that Jack was merely "in talks," but that no decisive contract had been signed. On Monday, NBC Chairman Bob Greenblatt responded to the controversy by asserting that the network does not discriminate, and that the show required all participants to undergo medical vetting due to the strenuous physical activity. Although Jack apparently wasn't asked to participate in the competition, he was offered "two substantial alternatives, both of which he declined."