Some 200 Texan patriots, surrounded by a huge enemy army outside their fortress, elected to fight to the death rather than surrender. That’s the story that comes down to us from bad 19th-century poets, Hollywood filmmakers and any number of respectable historians. That’s why, 166 years after the slaughter of its defenders, we still remember the Alamo.

However, the traditional version of the Alamo story has come under increasing scholarly scrutiny. Since the surfacing of a document purported to be the diary of a Mexican officer who was there, a fiery debate has erupted among historians about what really happened. Did all the Texans fight gallantly to the end, or not?

The purported diary of Mexican Lt. Jose Enrique de la Pena – now in a library at the University of Texas at Austin – claims not. It says about 60 defenders tried to escape over the Alamo walls and were shot down as they fled. Furthermore – and this is the claim that really stings traditionalists – the diary says the most famous defender, David Crockett, didn’t go down fighting. He and a few others surrendered and, upon Santa Anna’s order, were executed.

In “Unsolved History: The Alamo,” the Discovery Channel wades into the fray, but adds more murk than light to the debate. In typical TV documentary style, historians on both sides offer their opinions, but in such brief sound bites that they’re sometimes incomprehensible. And some of the claims that the narrator makes, perhaps in a nod to political correctness, will raise scholarly eyebrows.