Sinovac could design the protocol, criteria, and procedure if it wanted to. However, Sinovac decided to let Butantan institute to design the protocol to earn trust. However, Bolsonaro replaced his health ministry and the people in charge of anvisa and told the Blutantan to publish the lowest number as the trial results.
One of the mistakes is to allow Butantan institute to test everyone including asymptomatic cases which is abnormal. Initially, Butantan published the efficacy rate without including the asymptomatic cases but Bolsonaro and his people in anvisa forced Butantan to include asymptomatic cases and every Western media since then have used the 50.4% efficacy rate to mislead the readers.
Quote from the media "Normally, that is based on people developing obvious symptoms but in this Brazilian trial, people with no symptoms also appear to have been included." It is not only lack of experience but also foolish as some Western vaccines only include people with two symptoms for calculation.