While speaking about the type of wounds in the autopsy room, they identify the wounds as being from frangible bullets. They also state they can only be fired from a special weapon specifically made for them. Frangible bullets are made to disintegrate when it strikes a body. This is to keep from over penetration and cause significant tissue damage. However, it does not take a special weapon to use them. They are made in a variety of calibers as well as for both handguns and rifles. They are used in law enforcement and for hunting.
Near the end of the episode, there is a shot of an ambulance. The writing is written so a person looking directly at the vehicle would be able to read it. However, all ambulances in the US are required to have the writing on the front hood be reversed so a vehicle in front is able to read it through the rear-view mirror.
In the opening scene, a sight-seeing duo are tracking a black-tailed deer (Latin name: Odocoileus hemionus columbianus) in the vicinity Washington, DC, before locating a human corpse. Black-tailed deer can only be found on four American states (Alaska, California, Oregon, and Washington state) and one Canadian province (British Columbia). The species was formerly also present in Wyoming, but the local population of deer was hunted down to extinction.
In the beginning of the episode, a couple is traveling along a forest road and nearly hit a deer. When the lady exits the car to take a picture, she says, "Isn't she beautiful?" The camera then shows the deer, a black-tail doe. Blacktail Deer are native to the Pacific Northwest and are not found in the wild on the East Coast.
When McGee searches for "capitol crossroads press" using Google, the page displays their location as Los Angeles, CA. It should be Washington, D.C.
If any insurgents should want to "wipe out entire villages" in Afghanistan, why would they purchase exotic, unknown American gun prototypes on Cyprus and smuggle them across several international borders when they could just pick up any number of AK-47s and other old Soviet weapons that already are in Afghanistan? They'd kill the people just as dead and are available at every Afghan street corner for about $100 a pop. Also the ammo is much cheaper and certainly does not "under-penetrate".
Abby tells Gibbs that suxamethonium chloride (sux) is only used in one medical specialty because of its side effects. Certainly sux must be used carefully, but it has a role in more than one medical specialty within both human and veterinary medicine and has had since the mid twentieth century. It is used a great deal in hospital settings as a very short-term muscle relaxant for unconscious patients. It's a staple of anesthesiology, as part of surgical general anesthesia. At the time the episode takes place, Abby would certainly know all this and not make such a mistake.