Nadezya Ostapchuk was sentenced just to one-year suspension

The Belarusian shot putter Nadezya Ostapchuk received the gold medal at the 2012 Summer Olympics. But she failed a drug test. As a result, she forfeited the medal which was given to Valeria Adams of New Zealand.
Two tests displayed that a steroid’s metabolites presented in her urine samples.
When an athlete is caught administering any prohibited substances, he/she is usually sentenced to a suspension of two years. When it comes to this Belarusian shot putter, she received one-year suspension. Why was the sentence lighter? There were some circumstances which proved the following condition: Nadezya Ostapchuk didn’t use any forbidden preparation knowingly.
At the beginning Nadezya Ostapchuk blamed his former coach. She confirmed that he had sabotaged her sample.
The Belarusian National Anti-Doping Agency investigated this case. The International Association of Athletic Federation also participated in the investigation. It was found out that Yefimov was guilty. This person added powder of methenolone into food of Nadezya Ostapchuk during the last week before the 2012 Summer Olympics. The coach affirmed 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 agencies accepted these arguments. That’s why the Belarusian shot putter 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 knowingly. They confirmed that Yefimov just put efforts to protect the shot putter. They claimed that the Belarusian shot putter had taken steroids under recommendations of her coach.
If Nadezya Ostapchuk’s performance was amazing some months before the 2012 Summer Olympics, her coach had to be sure that she would win. Why did he worry about her performance?