I don't know if this was from the same episode (although, I'm sure it was and I just don't remember), but they did the 'melting a guy in acid' test and they recreated the Walter vs. Tuco and his henchmen scene (from S1) to see if Walter could really make a bomb and do that kind of damage. And yeah, I know my description of that scene is horrible.
The other tests failed though. They couldn't recreate them.