i think not willing to retract the study and agreeing with all the results is something very different: science is all about making mistakes, and pointing them out in other studies. That is how progress is made. If all scientists were to retract their studies once mistakes are found, this would result in an erasing of history that is very 1984 Orwellian.
As the authors did their work in good faith, and optimally made use of the knowledge that at this point was available, they should not retract their study.