Edited to reflect why I feel this question is on-topic here.
The following is excerpted from Politico's Appeals court deals setback to Flynn’s attempt to end DOJ case against him:
The D.C. Circuit Court of Appeals, sitting en banc, voted 8-2 to reject Flynn's effort to dismiss the case immediately. The court’s ruling Monday also rejected efforts by Flynn to remove District Court Judge Emmet Sullivan from the case over allegations of bias.
The unsigned majority opinion rejected arguments from Flynn and the Justice Department that Sullivan gravely intruded on executive branch authority by allowing the planned hearing and inviting a presentation from a retired judge whom Sullivan appointed to argue against the government's motion to dismiss the case.
The majority opinion noted that the dissenters initially rejected Flynn’s request to have Sullivan’s case reassigned to another judge, but in Monday’s ruling said such a reassignment was merited.
"It is the trial judge’s conduct since the government’s May 2020 motion to dismiss, weighed in light of his earlier conduct, that delivers the coup de grâce to the last shred of the trial judge’s appearance of impartiality," Henderson wrote.
Borrowing a vivid phrase from Henry David Thoreau, she went on to describe Sullivan's decision to seek en banc review of the initial appeals court ruling "the trout in the milk." Although she voted against removing Sullivan from the case just a couple of months ago, in Monday's ruling she accused him of "glaring partiality."
Quora's What does the phrase "a trout in the milk" mean? explains:
The meaning is that although you did not see the dairy farmer do it, he most probably dipped the milk pail in the stream to water down the product. It’s not direct evidence but a very strong circumstantial case.
It is attributed as follows: "Some circumstantial evidence is very strong, as when you find a trout in the milk. ‘ (Henry David Thoreau)
I sometimes have trouble parsing analogies, and it's especially challenging when the topic involves carefully written legal opinions and potentially political motives of federal judges. So I'd like to ask:
Question: What exactly is the "Trout" in this D.C. Circuit Court of Appeals opinion? Is it the other opinion in toto or something specific within it, or in fact something else? Does the opinion suggest that the judge has a political motive?