The mere fact that he thought he had immunity when he gave them nothing for it in return is absolutely 100% proof that they're colluding.
Not just to go as easy on him as possible, but to remove him from any investigation (as in testifying) that could drag in Dementia Joe, Hillary, Kerry, or even the sainted one of their party, Barrack Hussein Obama. Because if Joe was doing all the things it looks like he was doing, BHO had to know about it.
All of this covering up is most likely being done to protect Obama. The DNC couldn't give a rat's rear about Dementia Joe. He's gone as soon as they figure out how to do it, and without having to make Commie-La the presumptive nominee.