فَسَجَدَ الْمَلَائِكَةُ كُلُّهُمْ
“So the angels prostrated—all of them.”
Had the wording merely referred generally to the angels, a question about excluding certain members of that class might arise in textual analysis. The addition of kulluhum expressly includes each and every one in the action.
According to the book's footnote, this emphatic term shuts out takhsis in this instance. The analysis is about the scope of the original statement, not about inventing outside assumptions to alter the verse.