Or at least it can be interpreted that way. The memo in question is the one Mark Sumner wrote about earlier on the first page. Instead of adding this information as a comment, it seems significant and pithy enough to deserve it’s own diary.
The Week has the story, taken from the Washington Post’s piece about the Mueller’s response to Manafort’s lawsuit claims. The critical bit:
Throughout the document, Mueller's team spells out over and over why it had the authority to investigate and charge Manafort, The Washington Post reported. Attached to one of those defenses was a footnote:
The Special Counsel also has "the authority to investigate and prosecute federal crimes committed in the course of, and with intent to interfere with, the Special Counsel's investigation, such as perjury, obstruction of justice, destruction of evidence, and intimidation of witnesses" ... Those authorities are not at issue here.
That note uses language from a redacted memo that spelled out Mueller's authority in completing the investigation. The Post's analysis suggests that beyond the sass, the footnote could be a warning to President Trump — a promise that Mueller will finish this investigation no matter who gets in the way.