As the Fourth Amendment requires a willful violation, a training officer who forgets to swap his gun for a dummy gun and shoots the other fellow in the chest does not violate the Federal Constitution by restricting his freedom of movement.
http://www.ca5.uscourts.gov/opinions/pub/17/17-60515-CV0.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.