"Yes, sir.

"There was already a duel going on when I arrived. It appeared that Li--Evans had stopped fighting to assist Macdonald.

"I cast Petrificus Totalus on Avery when I arrived. From behind and without warning."

In the interest of being completely honest.

"It seemed the most expedient way to end things without anyone being permanently harmed.

"That was the last spell cast, aside from my casting the countercurse before Mulciber and Avery left.

"A handful of insults were exchanged, Evans took 100 points from Slytherin, told them Slytherins leave, and they did.

"She and I took Macdonald to Slughorn's office, to report what had happened."