No, it isn't playing dead. Boston Dynamics' robo-dog Spot experiences a technical failure at Amazon's Re:Mars conference.
Veteran Demos Advanced Prosthesis
Mr. Fred Downs demonstrates how he can use different grips on the DEKA Arm System to open and handle mail. The system was developed by DEKA Integrated Solutions for DARPA's Revolutionizing Prosthetics program. On May 9, 2014, the U.S. Food and Drug Administration approved the system for commercialization. More information: http://www.darpa.mil/NewsEvents/Releases/2014/05/09a.aspx