Nadezya Ostapchuk has to serve one-year ban

The Belarusian shot putter Nadezya Ostapchuk received the gold medal at the 2012 Olympic Games. But she failed a drug test. As a result, she lost the medal which was given to Valeria Adams of New Zealand.
Two tests indicated presence of a steroid’s metabolites in her urine samples.
If an athlete is caught using any banned drugs, he/she is commonly sentenced to a suspension of two years. As for Nadezya Ostapchuk, she received one-year ban. Why was the sentence lighter? There were some circumstances which proved the following aspect: the shop putter didn’t take any banned drug knowingly.
At the beginning Nadezya Ostapchuk blamed his former coach. She said that he had sabotaged her sample.
The Belarusian National Anti-Doping Agency examined this case. The International Association of Athletic Federation also took part in the investigation. It was defined that Yefimov was guilty. This person added powder of methenolone into food of the shot putter during the last week before the 2012 London Olympics. The coach claimed that he had worried about Nadezya Ostapchuk. He thought that this steroid would help to win.
Actually, it is difficult to understand why Yefimov has done it. He only caused the trouble.
Anti-doping officers accepted these arguments. That’s why Nadezya Ostapchuk received only one-year suspension.
As for supporters of Valeria Adams, they didn’t believe that the Belarusian shot putter had not used the steroid knowingly. They said that Yefimov just tried to protect the athlete. They said that the Belarusian shot putter had taken steroids under recommendations of her coach.
If the Belarusian shot putter’s performance was amazing several months before the 2012 Olympics, her coach had to be sure that she would win. Why did he trouble about?