Let me ask you something; If this is all for real, how do you see this playing out?
If Mueller is running interference for the Hillary/Obama axis, who is going to force him to acknowledge this as a real offer/exchange instead of just ignore it?
Yes, it will be ignored.
Mueller will ignore and disregard this offer by Putin. He has to. He cannot prove the charges against those 12 Russians. Unless of course he exposes the real truth of the Obama/Hillary collusion.
And he certainly would not want to see the Russians investigate the corrupt US officials that helped moved 400 million to the HRC campaign.
Especially as some of those guys are currently on his witch hunt crusade.
Putin called his bluff. And Mueller will fold.
As remarked up thread, POTUS could instruct Rosenweasel to evaluate the offer. When he does it in the weasel rat way, POTUS could charge insubordination and send him packing. There is already a pecking order of temporary replacements it the chain of DOJ command.