Oakey was getting really irritated with how everyone was pointing out that he was the only one who had cast a spell in this confrontation. No one really saw Laura about to cast Stupefy except him! That wasn't fair at all, in the end he would be the only one getting in trouble.

He glared at Laura as she spat her lies from behind Gideon. He didn't need to act like an ickle firstie and hide behind prefects. "I'm not lying!"
Oakey shot back at Laura gripping his hands tightly. "I was defending myself, and that's the truth. Laura provoked me, she pulled her wand on me first." He looked back at Gideon. The look of honesty all over his face. If there was one lesson learned it wasn't that you shouldn't cast spells at each other with a Prefect in earshot. It was that Oakey couldn't lie! His attempts to keep Felicity a secret from Laura were feeble at best. "I can't lie." He finally admitted.

He turned his head as everyone seemed to be worried about Laura and her broken arm. This could have all been avoided if she had not pulled her wand on him first.