There are reasons from that clip to support the conclusion that this is Tippit's notebook or citation book. Look at how they are holding it. Vertically as though reading from a note page. In fact a page from the object appears to blow up at the very end from the wind. That suggests it has paper pages like a notebook or citation book rather than a wallet. In addition, they appear to be reading something from the object even tracing it with a finger. If they were taking down a witness ID, they would be writing that information down. But there is no indication that they are writing anything down from the object. I've never seen anyone asked by the police for an ID to hand their entire wallet to the policeman. Typically, they would remove the requested item (e.g. license) and hand it to them. I'm not saying this is conclusive of the issue, but it lends itself in that direction. What it is not, however, is a wallet left at the scene.
So many words and it's all selfsevering speculation.
What you see "blow up at the very end from the wind" is the flap of the wallet.
Bottom line is still that FBI agent Bob Barrett, who was at the scene, said it was a wallet and the LNs can not even begin to explain why they would doubt what he said. In fact, they have no reasonable or plausible grounds to doubt his words, nor do they have anything else but speculation about what it could be if not a wallet.
What it is not, however, is a wallet left at the scene.Ok, mr. know it all.... surprise us all and prove (not with so-called "logic" or "common sence" but with actual evenidence it isn't a wallet!
Perhaps you can track down the uniformed officer holding the wallet and have him confirm it wasn't a wallet after all. That would do the trick. Go on then...