The core principle of science is trying to prove your belief incorrect. Mythbusters was basically trying to see if some story was plausible, and can we make the test interesting. Unfortunately this is very common even among scientists, but I using that basic principle it’s almost accidental when they learned something was different than they expected.
A great example of this is their sword breaking setup. Take two swords and whack them together seems like a natural test. Unfortunately, the issue isn’t the strength of the sword when new it’s a question of metal fatigue and defects in craftsmanship. But, rather than run the test for say 2 weeks they just increased the swing strength because that looks cool.