14. 626 (5th C6.2006). "Estate of Dunn v. Commit; 301 F.3d 339,348 (5th Cir. 2002). "Adams v. United States, 218 F.3d 383, 385-86 (5th Cir. 2000). B. Framework I. `Co Special Deference Preliminarily. we note two factors that do nor come into play in today's review. First. the Tax Court neither expressed no