In fact he did.
You're correct that when the subamendment was proposed a new speakers list started. As people raised their hands to speak on the subamendment, the clerk recorded that. Mr. Del Mastro raised his hand but ceded his spot to Mr. Butt, who wished to speak. So the current list is Mr. Butt, Mr. Del Mastro, and Mr. Andrews.
Mr. Butt was in the process of moving a motion.