I’ve thought all along that Jeff Sessions was the insurance policy.
There is another possibility, Trump could have known they would try to impeach him as early as December 2016
https://en.m.wikipedia.org/wiki/Efforts_to_impeach_Donald_Trump
In December 2016, Democratic Senators Elizabeth Warren, Dick Durbin, Chris Coons, Ben Cardin and Jeff Merkley introduced a bill that would require the President of the United States to divest any assets that could raise a conflict of interest, including a statement that the failure to divest such assets would constitute high crimes and misdemeanors “under the impeachment clause of the U.S. Constitution.” Vanity Fair characterized this as a preemptive effort to lay the groundwork for a future impeachment argument.Concerns had previously been expressed that Trump’s extensive business and real estate dealings, especially with respect to government agencies in other countries, may violate the Foreign Emoluments Clause of the Constitution,sparking debate as to whether that is the case.
Session didn’t recuse until 3 months later March 2 2017
So while possible session is a doofus he also could have decided to recuse so that he could be Trump’s attorney at any potential impeachment hearing.