Late November Judge Richard Leon rose to the bench in his Washington, D.C., courtroom for what was expected to be a routine hearing as the Justice Department sought final approval of a settlement clearing CVS Health Corp.’s acquisition of Aetna Inc.

The hearing was supposed to address the appointment of an outside monitor to oversee the divestiture of Aetna’s prescription drug plan business, a condition of the Justice Department’s approval of the $69 billion merger. But Leon apparently had more on his mind.