He may not have coached him as closely as Neeraj Chopra but Shivpal Singh's second doping offence has infuriated celebrated German bio-mechanics expert Klaus Bartonietz, who cannot make sense of the Olympian's "stupid" conduct while claiming to be a proud representative of India. Bartonietz lambasted Shivpal for "cheating" despite coming from a proud sporting family. The German bio-mechanics expert, who guided Chopra to a historic gold at the Tokyo Olympics and a silver at the Paris Games, didn't hide his anger as he lambasted Shivpal for a second doping offence that could lead to an eight-year ban.