The character of Caboose (blue armor) was originally not supposed to be "the stupid one." He was essentially a mere counterpoint to the Red Team getting their own 'Rookie' Originally designed with only a hint of smarminess or chauvanisticness, the creators realized that the fans were commenting more on Caboose's "stupid" comments than anything else. Caboose is now considered by some to be the most popular character in the series.
The show's production company is called Rooster Teeth, which is another way of saying "cockbite," an insult commonly used on the show.
Geoff Ramsey, who voices Grif, is the only person involved in the show who has actual military experience - he served in the United States Army for five years.
At the end of episode six, Church and Tucker hide behind a rock to avoid the fire from the Warthog's gun, remarking "That thing's gotta run out of bullets some time." At the beginning of the next episode they are still waiting there, still being fired on, and say "Doesn't that thing ever run out of bullets?" This is a reference to the fact that in the game Halo, the vehicle-mounted guns magically never run out of ammunition.
The Spanish spoken by Lopez is frequently incorrect, usually by misusing articles or mixing up the order of the words in a sentence. This is because lines written for Lopez were translated from English to Spanish through Babblefish. The most usual errors are in the translation of some English expressions done word by word, instead of using some Spanish expression with the same meaning. That causes the fact that sometimes the sentences in Spanish have no meaning at all. This is also true of the occasionally-spoken French.