They would have had to come up with some sort of cover story. One would be beyond foolish to take their word on it, especially when considering all the rest. And who would have done the "investigating"? The Obama-Hillary admin.
Right, it’s worth looking into. But given the nature of the nuclear materials black market, it would take a real smoking gun to break it. These people know how to do their paperwork.
Here’s a story from the time of the original event:
https://www.reuters.com/article/us-nuclear-georgia-arrest-idUSL2575690620070125
and a report of CIA-FBI involvement in the sting: