I went looking for support for Albaby's "correct interpretation" of official acts, and while I don't like the juggler example, it gets the point across. Criminal acts by definition cannot be official acts. Published yesterday in National Review, it agrees with my first idea while reading about the decision, then Albaby buttressed the idea, then I had doubts because some prominent legal scholars were taking the immunity for all official acts except clearly personal acts.

SNIP The first idea, which I will tendentiously call the “correct interpretation,” is that criminal acts by definition cannot be official acts. The president is endued with certain powers by the Constitution; Congress, therefore, may not criminalize the exercise of those powers; and whatever Congress does legitimately criminalize must by definition fall outside the scope of the president’s powers. There is no harm in thinking that presidents have immunity from criminal prosecution for official acts, since this is just to say that they may do what the Constitution (or in some cases the Constitution along with Congress) lets them do; nor will thinking they are thus immune compromise the enforcement of criminal law, since what is criminal by definition cannot be an official act. A president might commit crimes, yes, but if so he does this not as the president but as a private individual, even if his crime is performed simultaneously with a genuine official act, and even if it is the same physical performance under a different description. It is somewhat as if the president knew how to juggle and liked to juggle at cabinet meetings for the pleasure of his advisers while giving instructions to cabinet officials. He does not thereby make juggling part of the official act of giving instructions to cabinet officials; he juggles as a private individual while giving instructions as the president, and Congress is free to regulate juggling for everyone, including the president, however (absurdly) it deems necessary. SNIP

Haven't finished reading the article, thought I'd post this part first. :)

nationalreview.com - Trump v united states what are official acts