Beulah Koale has previously played another role in the JAGverse: Junior Reigns on Hawaii Five-0 (2010).
Thallium is a chemical element, it is a post-transition metal in the same periodic group as boron, aluminum, gallium and indium. Thallium has several practical applications, it is used to make optics for infrared cameras, is also heavily used in electronics as an electrical conductor and is used in nuclear medicine in the form of thallium-201, a radioactive isotope of thallium that is used as a contrast dye for nuclear imaging of the cardiovascular system. Thallium is also highly toxic and a well known poison, up until the 1970's it was the main ingredient in rat poison until it was outlawed due to it being frequently used to intentionally poison people. Thallium was a popular poison because the thallium salts are easily absorbed through the skin and are also odorless, colorless and tasteless so they could be put in food and drink without being noticed; thallium poisoning (when low doses are used) causes a slow, painful death and has a wide-range of symptoms that can make it appear as any number of illnesses and conditions. Thallium shares some chemical similarities with potassium, as such it is absorbed in the body through the same route as potassium, when thallium is absorbed through potassium pathways it blocks them, preventing cells from using potassium to make certain proteins that are essential for cell metabolism and survival. Cell death starts causing damage in the peripheral nervous system, and presents at first with the symptoms of hair loss and painful burning sensations in the extremities with lower dosage exposure over a period of time. However higher doses cause death before those symptoms appear, damage to the central nervous system occurs after a period of time with low doses of thallium and immediately with high doses. Cells in the nerves that transmit signals from the brain to major organs like the heart, lungs, liver and kidneys begin to loose function which eventually results in death. Depending on the dose used and route of administration thallium poisoning can take anywhere from a few months to just a few hours to cause death.
The intelligence operative from New Zealand mentions that he is not sure why US Marines are called "jarheads". Jarhead started as Navy slang for Marines, as the Marine Corps and the Navy have always had a friendly rivalry, it was meant as an insult, in a friendly joking manner, but the Marines proudly adopted the term as their own. The term first appeared around World War II and referred to the Marine Corps dress uniform, specifically the uniform's high collar which runs all the way up the neck and ends with the Marine's head popping out the top; which a lot of sailors thought made them look like a Mason jar, hence the term "jarhead".
Known for playing American character Junior Reigns in Hawaii Five-O, Beulah Koale uses his native New Zealand accent in the two-part episode. He is New Zealand born and of Samoan heritage.
Beulah Koale is known for playing Junior Reigns in Hawaii 5-0 - a Hawaiian who returns home after finishing in the U.S. armed forces to a law enforcement role in Hawaii 5-0 similar to one of the main characters in NCIS Hawaii, Kai Holman played by Alex Tarrant. In real life there is also a similar background as both actors are actually from New Zealand with their 1st big international roles in these Hawaii based shows/roles.