The reaction came after the IOC lifted the Russian Olympic Committee's suspension over widespread state-sponsored doping on Wednesday.
Rodchenkov's US lawyer Jim Walden told CNN that the IOC and its president, Thomas Bach, "treat Russia and its glaring acts of aggression with cowardice and appeasement."
"Weakness in the face of evil results in no good outcomes," he added. "What Russia did at Sochi was evil directed at the Olympics and clean athletes. Its reaction since -- lies, blame, threats and retaliation -- is a broader form of evil."
Rodchenkov, the former head of Moscow's anti-doping laboratory, fled Russia in 2015 and is currently enrolled in the witness protection program in the US.
CNN has reached out to the IOC and the Russian Olympic Committee for comment.
'No evidence of systematic doping'
The IOC reinstated Russia even though two of its athletes failed drug tests during the Games, which ended on Sunday.
IOC president Thomas Bach said the two failed tests, from curler Alexander Krushelnitsky and bobsledder Nadezhda Sergeeva, were "very disappointing."
However, Bach stressed there was no evidence of systemic doping and no evidence of the involvement of the Russian Olympic Committee" in either case.
"I have never either violated the rules of sports or used doping," Krushelnitsky said in a statement published by TASS after handing back a bronze medal he had won alongside his wife Anastasia.
Meanwhile Stanislav Pozdnyakov, head of the team of Russian athletes who competed at the Games, assured the IOC the positive tests were "more to do with negligence than malicious intent."
Russian Olympic Committee (ROC) president Alexander Zhukov spoke of the effort it had taken to get Russia reinstated and called the decision "very important."
"You know that the past three months have been among the most challenging ones in Russian sport's history," Zhukov said Wednesday, in comments carried by Russian state news agency TASS. "We had to meet many demands before and during the Games."
"I would like to thank our athletes who were able to perform well even despite the provocations," Zhukov added. "I thank the fans who did not cross the line and what could result in sanctions.
"Today's IOC's decision is very important for us. The ROC is an absolutely full-fledged member of the Olympic family."
Russia was banned from PyeongChang 2018 following state-sponsored doping, leading up to and including the Sochi 2014 Winter Olympics.
However, a team of 168 athletes who proved they were clean competed under the Olympic flag as Olympic athletes from Russia (OAR).
The OAR team finished 13th in the medal tables at the winter games -- winning two golds, nine less than Russia captured in 2014 in Sochi.