This was clearly "Julius's" gesture of submission to Annan.
For mortals, it might feel somewhat embarrassing to first claim innocence and powerlessness under Ingrid's control and then to admit that there had been numerous collaborations between the two.
But Annan knew that this was, in fact, a sign of sincerity.
"Julius," having completed Soul Mechanization, could make decisions unaffected by momentary madness or greed, and could regard matters with absolute public objectivity, without the influence of emotions or personal stance... But that didn't mean he wouldn't lie, nor did it mean he wouldn't betray.
If the opportunity was right, the timing appropriate, the risk low, and the profit high—then "Julius" would act accordingly.
At first, "Julius" rationally decided it was most beneficial for him not to mention this matter, hence the concealment; once the topic was broached, however, he provided honest answers to all questions.
