Tahmoh Penikett wanted to remove the controversial lines from the script in which his character stated that the Cylons tried to live in peace with humans in New Caprica, because he thought Helo couldn't agree with that. However, the lines were kept.
Lymphocytic encephalitis is an actual disease caused by the Lymphocytic Choriomeningitis Virus. Encephalitis is the acute inflammation of the brain. Brain damage and death can occur as a result of the inflammation. As Doc Cottle stated in the episode, it is usually carried and transmitted by rodents. Unlike the Colonial survivors, humans on Earth are not immune, although infection does not result in symptoms in most healthy adults. It can, however, be deadly for persons with compromised immune systems.
Admiral Adama states that the 13th Colony left Kobol at least 3000 years ago.
Tahmoh Penikett (Karl "Helo" Agathon) read the "Previously on Battlestar Galactica" line at the beginning of this episode.
Human Survivor Count: 41,420