why wasn't Billy Welch prosecuted?

I posted the text of the arrest report of Marco Thomas and Billy Welch, Proviso West's new night custodian.

I thought it was odd Billy Welch didn't get prosecuted. I considered it possible that Billy Welch was the informant that gave the DEA the tip. It seems obvious that the DEA agents had a tip since the car they nominally pulled over for erratic driving had 240 grams of crack cocaine. What are the odds of the DEA pulling over a car on the flimsiest of pretenses and finding 240 grams of crack?

I didn't want to go public with the hypothesis Billy Welch was the informant because it might put him at some risk. I now consider it unlikely he was the informant.

I called the State's Attorney's press office and asked about the Billy Welch case. I learned that Chris Welch used to work in the State's Attorney's press office.

Chris Welch is the brother of Billy Welch. Chris Welch used to work for the State's Attorney. Chris was Billy's defense attorney in this drug possession case. And Chris is the president of the school board that just hired Billy.

Eventually the State's Attorney's office made the claim that the case against Billy Welch was dropped at the request of the U.S. Attorney's office. This had me thinking Billy was the informant.

But then I called the U.S. Attorney's press office. The U.S. Attorney's press office explained that the initial drug possession charges were filed in Cook County, but that the U.S. Attorney took the lead on prosecuting Marco Thomas. The U.S. Attorney never had anything to do with Billy Welch, in this case.

I called the State's Attorney's press office back. She said the U.S. Attorney prosecuting Marco Thomas presented an "impediment" to prosecuting Billy Welch. She was claiming that there was no difference between what she was telling me in the two different conversations.

I was getting annoyed with her and suspected I was not getting the truth. I kinda lost my cool and accused the State's Attorney's office of covering for Billy Welch. She told me, I was making "serious allegations". No shit?

I consulted with an attorney friend who is also a prosecutor. He said the State's Attorney's story didn't make sense.

So here's why I figure Billy Welch was not the informant.

1. If he was the informant merely dropping the charges against him would be sorta obvious. A and B gets arrested together based on an inside tip. A gets prosecuted big time and B doesn't get prosecuted at all. Who's A gonna suspect of giving the tip?
2. If Billy Welch were the informant I'd expect the State's Attorney to have a rehersed explanation of why he wasn't prosecuted or "no comment". Does it make sense to give a series of inconsistent explanations that are bullshit.

So if Billy Welch wasn't the informant, why wasn't he prosecuted?

Did the State's Attorney's office just drop the charges?

Was this a favor to Chris Welch?

Or is there a ring of drug dealers that can get charges dropped at the county level?