Physicist: How Long Would It Take for an AT-AT to Fall?

For a long time, I've suspected that much of the footage of the Battle of Hoth was digitally altered. Now physicist Rhett Allain gives me reason to have those doubts. He's crunched the numbers and determined that the AT-AT that Luke Skywalker allegedly destroyed was actually a model. How can Prof. Allain be sure? Because a real AT-AT would have taken longer to fall over:

According to this, how tall would the center of mass have to be in order to just take 3.5 seconds to fall over? It would just be about 9 meters tall. So, here are my options.

The gravitational field on Hoth is not like Earth. I crunched the numbers (re-ran the calculation) and you would need g to be about twice the value of Earth’s in order to get a tip over time of 3.5 seconds (starting from 5 degrees). However, this would not agree with the falling Luke.

The center of mass of the AT-AT is not where you think it is. This could be the case if the legs were super massive. Why would they be so massive? Who knows? (well, maybe George Lucas would know)

The AT-AT is not 22.5 meters tall but instead like half that height. Of course, this wouldn’t agree with Luke’s fall time.

The AT-AT didn’t actually tip over. Instead, it was an inside sabotage job by some disgruntled Storm Troopers. Wait, this wouldn’t explain the fall time.

So, you see there are some problems with this scene. I guess the only reasonable thing to do is to make a new version of The Empire Strikes Back. In this new version, the AT-AT would take another second to fall over. Sure, this might be a lot of work to redo the whole movie for just one scene – but think of all the new Star Wars Blu-ray sales.