Touchstone - S2-E14
Corrected entry: When SG-1 retrieved the Touchstone in Nevada after the thieves escaped through the second gate, why did they not just take the Touchstone back to Medrona using the second gate? Considering the world was on the verge of destruction, they thought they would have the time to fly back to Colarado and use the gate at stargate command. The NID guys escaped through the second gate right before SG1 got the Touchstone. And there was a DHD connected as well, so all they had to do was enter in the address on the DHD.
Correction: Because it would be suicide. Getting to Medrona would be fine, but when they got back they would find themselves a smear on the inside of the iris. They didn't have their GDOs, why would they, they are on Earth.