Noah Wyle is absent for most of the next 6 episodes as he was given leave to spend more time with his family.
Luka's badge picture is actually a photo taken of Goran Visnjic when he was promoting his film The Deep End (2001) at the Sundance Film Festival.
The incredibly moving music playing as Luka prays in his native language (Croatian) is "Agnus Dei", by the American composer, Samuel Barber, II. It is Barber's vocal arrangement for chorus of his immensely popular "Adagio for Strings", originally set for string orchestra.
Hawaii doubled up for the Congo.