Listen to the whole thing, especially if you haven't been keeping up. Dan covers the whole chain of events, from the NSA shutting down FBI contractor access to their database (were some of those contractors Fusion GPS and Nellie Ohr?), to the efforts to get a FISA warrant based on the dossier that likely came from that NSA database (due the Michael Cohen in Prague mistake), to the efforts to set up Page and Popadopoulos, to the Trump Tower meeting setup.
He picks up on a couple new points that I had missed. One is that Nellie Ohr was working for Fusion GPS all the way back to 2015. That means she was working at Fusion GPS while the FBI contractors (still unspecified) were abusing the NSA database (85%!!! of the accesses to the database did not comply with the appropriate privacy procedures).
A second is that Andrew Weissman was being kept in the loop by Bruce Ohr during the investigation and was then hired by Mueller for his special counsel investigation. So, Weissman (along with, at least, Peter Strzok and Lisa Page), was effectively investigating events he was involved in and likely has criminal liability in. And Weissman is still on Mueller's team.
Finally, Bongino goes through the links Mueller has to practically every significant figure involved in this case. Mueller is linked to Comey, to Russian oligarchs who helped the FBI investigate, to Hillary lawyers... the list goes on and on. Mueller practically knows every key player personally.
Is he going to rat on his friends? Of course not.
He's going to sweep the whole thing under the rug by keeping the focus on Trump.