He may not have coached him as closely as javelin super star Neeraj Chopra, but Shivpal Singh’s second doping offence has infuriated German bio-mechanics expert Klaus Bartonietz.

Bartonietz, who shared a highly successful five-year partnership with Chopra during which the Indian collected a host of accolades, including a historic Olympic gold at Tokyo and a silver at the Paris Games last year,  didn’t hide his anger at Shivpal’s second doping offence that could lead to an eight-year ban. “Disappointed? I don’t know. But I’m really pissed off. So stupid,” Bartonietz told PTI on Wednesday.