Around the 7:23 mark Morgan says that with the position of the last person shot it looked like he was facing North. The photo of the victim Morgan is looking at is with the EMTs working on the victim. When this victim fell he was 3 feet away from benches, and a trash can, with his head to the left of the image, and face down. The photo Morgan is looking at, the EMTs have obviously moved this man away from the benches and trash can, and have also moved his head from the left of the image so his head is now to the right side of the photo Morgan is looking at. The photo Morgan is looking at would not give him an accurate idea of which way the man was facing when he was shot.
(at around 23 mins) When Dr. Reid walks through the slow motion of the shooting, victim #3 puts her hand under her head when shot dead.
The gun the sniper uses is referred to as a "semi-automatic assault rifle." However, both times the sniper's rifle is actually shown, it is a bolt action rifle.
Hotchner initially mistakenly refers to the shooter both as a "sharpshooter" and as a "marksman" - neither is a common word for shooters but both are military terms referring to the same specific profession: a medium range shooter that is attached to an infantry unit and is not required to work alone or use stealth.
Other characters correctly refer to the unsub as a sniper: a long range shooter that works alone and is proficient in evading tracking and discovery.