Belarusian shot putter should serve one-year suspension

The Belarusian shot putter Nadezya Ostapchuk won the gold medal at the 2012 London Olympics. But she tested positive for a steroid. As a result, she was stripped of 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 applying any prohibited preparations, he/she is usually sentenced to a suspension of two years. As for this Belarusian shot putter, she received one-year ban. Why was the sentence lighter? There were certain circumstances that proved the following condition: Nadezya Ostapchuk didn’t apply any forbidden preparation intentionally.
At the beginning the shot putter 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 assisted the investigation. It was determined that Yefimov was guilty. This person put powder of methenolone into food of Nadezya Ostapchuk during the last week before the 2012 London Olympics. The coach claimed that he had worried about the shot putter. He believed that this steroid would help to win.
In fact, it is difficult to define why Yefimov has done it. He only caused the trouble.
Anti-doping officials accepted these affirmations. That’s why Nadezya Ostapchuk was sentenced just to one-year ban.
As for supporters of Valeria Adams, they didn’t believe that the Belarusian shot putter had not used the steroid intentionally. They affirmed that Yefimov just tried to protect the shot putter. They claimed that Nadezya Ostapchuk had taken steroids under recommendations of her coach.
If the Belarusian shot putter’s performance was amazing certain months before the 2012 Summer Olympics, her trainer had to be sure that she would win. Why did he trouble about?