However, it only said that 调查组 can recommend the sacking of the person being investigated. It does not mean "no one else cannot do it". In this case, there has been a long investigation. As the result of that investigation, Bo was sacked. Now the 调查组 started 立案调查. I still do not agree with your conclusion that someone is violating the rules, unless you showed me "only 调查组 can sack an official".
I would argue that a person should be sacked as soon as possible once clear evidence against that person is revealed because the person can use his power to do more harm or escape.
As long as the final punishment is not given, there is no issue of 冤假错案. The person under investigation simply enjoys free his vocation.
