From what I've been told, Tulane made an unbelievable offer. LSU and Bama were talking "official visits" as was Southern Miss, New Mexico and others but he made his decision prior to all of that happening. Also heard that LSU and Bama couldn't touch the offers he got from UL and Tulane. Then Tulane lost the coach who was recruiting him to the Univ.of Houston and that likely left them out.
Don't shoot the messenger; just what I've heard from reliable sources.