How could steroid dealer Mihael Karner avoid extradition to US?

Lately a large steroid chain was busted in Austria. It was discovered that this company received 40 million Euros due to illicit distribution of steroids. Mihael Karner was claimed to be the leader of the steroid ring. The USA asked Austrian authorities to extradite this person to the US. But the steroid dealer avoided the extradition successfully. This person gave one million Euros to Austrian authorities that sent him to his native country Slovenia.
Slovenia’s laws differ from Austrian ones. According to the Constitution of this country, it is forbidden to extradite Slovenian citizens to another country. Mihael Karner is a lucky individual. If he had been extradited to the USA, he could be sentenced to 40 years in jail.
Federal prosecutors started the investigation related to this steroid empire in 2005. The steroid ring started to function earlier. Federal prosecutors determined that since 2000 till 2008 the company got 40 million Euros due to illicit distribution of steroids.
Federal prosecutors determined in 2005 that Mihael Karner and his wife were involved in illicit sale of steroids but they couldn’t pursue them because the Karners were in Austria. But later steroid laws in Austria were changed due to suppression by the US. Moreover, the US induced the arrest of Mihael Karner and his wife.
Although the US attempts to enforce other countries of the world to extradite distributors of steroids to the USA, it doesn’t have significant success in this area. But the persons that were implicated in “Musclebear” and “British Dragon” were extradited from Cyprus and Thailand to the USA. That time the US celebrated its victory.
As for Mihael Karner, the USA supposed that the extradition would be successful. That’s why the US was shocked, when it was found that Karner reached Slovenia safely. So, the USA was defeated this time in the war on steroids.