Decision of anti-doping officers about sentence linked with Nadezya Ostapchuk

The Belarusian shot putter Nadezya Ostapchuk won the gold medal at the 2012 London Olympics. But she failed a drug test. As a result, she forfeited the medal that was given to Valeria Adams of New Zealand.
Two tests showed that a steroid’s metabolites presented in her urine samples.
If a sportsperson is caught using any prohibited medicines, he/she is commonly sentenced to a ban of two years. As for this Belarusian shot putter, she received one-year ban. Why was the sentence lighter? There were some circumstances that proved the following condition: the Belarusian shot putter didn’t apply any forbidden drug intentionally.
At the beginning the Belarusian shot putter blamed his former coach. She confirmed 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 Olympic Games. The coach reported that he had worried about Nadezya Ostapchuk. He thought that this steroid would help to win.
In fact, it is difficult to define why Yefimov has done it. He only caused the problem.
Anti-doping agencies accepted these affirmations. That’s why Nadezya Ostapchuk received just one-year suspension.
As for supporters of Valeria Adams, they didn’t believe that Nadezya Ostapchuk had not applied the steroid intentionally. They affirmed that Yefimov just tried to protect the shot putter. They claimed that the Belarusian shot putter had taken steroids under recommendations of her coach.
If the Belarusian shot putter’s performance was amazing some months before the 2012 Olympics, her trainer had to be sure that she would win. Why did he trouble about?