At about 30 minutes in, when Walter broke the tube in his computer to transfer William Bell's consciousness out of Olivia, he went to his Zenith Circle of Sound stereo to get an ECL82 tube to replace it. But the Zenith Circle of Sound is solid state and only contains transistors and no tubes.
When Peter arrives in Olivia's mind (at about 11:00 minutes in), there's a shot of a person walking through a solid stone fountain rim.
At the time of this episode Olivia was 31 years old, which would have her birth year as 1980. The child version of Olivia was about seven years old.The army did not start using Humvees until 1989.
When Walter decides they need to take LSD for the journey to work, he asks Astrid to help mix up "2000 milligrams" of LSD, which is insane. He probably meant 2000 micrograms. A fairly large dose for one person would be 450mcg so, 2000mg/3/450mcg =~1.5 million times the recommended dose, which would likely cause permanent brain damage if it didn't kill them.