Because he turned off the surveillance!
When he saw Noreen and Daryl gearing up to mess with Rosemary, Jerome happened to walk into the tent. He quickly hit the remote to turn off the screen.
The screen was off, but the surveillance still recorded in real time. Jerome just couldn't see it.
"What the hell happened?" Lieutenant Madden freaked out, and his voice was tense. He looked at Roger, his eyes fiery, "What did your student do to Rosemary? Spit out the truth right now!"
"Lieutenant Madden, don't listen to his bull crap." Roger was more nervous now. He didn't understand why Lieutenant Madden was so pissed, but he felt bad.
On the other hand, Jerome angrily added, "Last time, it was his idea for the competition. Rosemary beat Noreen, and Noreen couldn't take it. Today, she probably wanted to get back at her, so Roger let her take her revenge on Rosemary behind the scenes!"
"You're framing me!"