They are trying to say this is alternative prosecution. There are several problems with this. One, they didn't give the Chicago PD any notification of what they were doing. Second, they had an emergency hearing to drop the charges. If this were a "normal" occurrence, why couldn't it be handled without the need of an emergency hearing where proper notification (and explanation to the Chicago PD of the reasons behind the decision) could occur?
When you take those questions into account with the fact that the prosecutors did not get any form of admission of guilt from Smollett (and he is still vociferously proclaiming his innocence), it seems unusual at best. As a comparison, Robert Kraft was offered alternative prosecution which would have dropped the charges against him but, he would have been required to sign a statement that he likely would have lost if it had gone to trial (which is at least part of the reason he turned it down). Add to that the fact that the case was sealed so the public doesn't know for certain what the evidence was against him (all we have are leaks that may not be completely accurate), which just causes everything to be completely shrouded in secrecy.
I have no reason to doubt the prosecutors' (including Foxx) intentions were good but, just looking at what I laid out here makes it difficult to argue with those that do. I do however, believe they were less than competent in how they handled both the case and the aftermath.