At approx 5 minutes into this episode which is set in June 1944, Nicola Tesla is standing in front of a blackboard clearly displaying a Feynman diagram...which were not introduced by Richard Feynman until 1984.
When Col. Korba shows his eyes to Helen she says the fire elemental has burned his retinas. The retina is the inside layer at the back of the eyeball that registers light, burning them would have blinded him. The red surface she is commenting on is the cornea. As a doctor, she would know this.