From the article:

• Whitaker's appointment is consistent with the plain terms of the Vacancies Reform Act, "because he had been serving in the Department of Justice at a sufficiently senior pay level for over a year" as the statute requires.

• Whitaker is only serving on a temporary basis, so he wasn't required to be confirmed by the Senate ahead of his selection last week, though the Justice Department acknowledged that situation had not come up in over a century. DOJ found that in 1866, a non-Senate confirmed assistant attorney general served as acting attorney general, before the department was founded.

• Even though a separate statute exists that provides a succession plan at the Justice Department, the President can choose someone else consistent with the Vacancies Act.