I am pretty sure that Peyton Manning has the resources to hold his own against a television network which has defamed him, which it what it will be if the story is false. He has already made noises regarding filing suit against them. Sounds like they single-sourced the "story," and if it turns out the guy was lying, Peyton will have a nice claim he can make against the network. He is certainly a public figure, but their disregard of the truth could very well be reckless or intentional which opens the door. As a person who has tried a couple libel cases to a verdict, and settled the others, if the story is demonstrably false, it would be quite a bit of fun to have a case called "Manning v. Al-Jazeera" waiting on the docket of a court in Colorado or Indiana or Tennessee or other places where he is well known.
I am only saying this because PM said he would probably sue them because he is really angry. That is, of course, no reason to sue somebody, but I presume his lawyers can advise him about it. If there is no lawsuit for libel filed by Manning, I would have to wonder why. It is okay to bitch about the unfairness, but there is a remedy. If you are not going to avail yourself of the remedy, then stop whining about how unfair it is and how angry you are. You have a remedy. Use it or shut up.
Has Al-Jazeera been asked to retract the story? If not, why not? Sounds like their source now says it is a lie, so they need to do the right thing.