McGloin was clearly joking around, but the point still stands. Though he's a first-year head coach, O'Brien has not been afraid to show in-game intensity and character so far this season. And that's something his players love about him.
Against Northwestern, officials flagged cornerback Stephon Morris for a pass-interference call on a broken-up pass, though replays showed there was little-to-no contact between Morris and the receiver.
A few plays later, Morris was down on the field with an injury, and O'Brien used that opportunity to let off some steam. After checking on Morris, O'Brien screamed at anyone who would listen, including the officials and what looked like Northwestern coach Pat Fitzgerald.
"No, no no, I didn't yell at Pat Fitzgerald. Nah," O'Brien said after the game to the laughter of the press room. "Nah, I was laughing at myself. That's all it was. I wasn't yellin' at anybody."
After the game, Morris said he doesn't know if it was a good or bad call, but he still appreciates O'Brien's intensity.
"We love coach O'Brien," he said. "We love his enthusiasm, his excitement. We know he's gonna be with us every play whether it's a good call or bad call."
O'Brien's rant got the crowd of 95,769 going. Though Northwestern would end up scoring a touchdown on the drive, O'Brien's screams had an impact on the team.
"It got me fired up," said senior center Matt Stankiewitch. "Seeing coach O'Brien doing that, it's just the way he is. He feels very passionate about what he believes in and his abilities of knowing football. So when he did that, we believed that what he's doing is what's best for the team."
That wasn't the first time O'Brien yelled at an official this year, as he has let them hear it on a few occasions throughout the season.
He has shown character in other ways as well: He didn't pretend he wanted to have anything to do with Illinois coach Tim Beckman after that game. Beckman, who sent coaches to Penn State to recruit players over the summer, received a total dead-fish handshake from O'Brien after the Lions embarrassed the Illini on their home turf.
And before O'Brien came to Penn State, he was perhaps best known for a sideline screaming match with quarterback Tom Brady when O'Brien was the New England Patriots' offensive coordinator.
"It's just good to have a coach who has your back," tight end Kyle Carter said. "We know he's going to fight with us through all of this. He knows that we got his back, so we just love to get that win for him, and we know he's real happy."
Both O'Brien and the players have elucidated at many points during the season that they have a strong mutual respect for each other. After another emotional win Saturday, Penn State's first over a ranked opponent at home since 2008, those feelings were put on display once more.
"They're smart. They're tough. They're committed to Penn State," O'Brien said of his players. "These guys are playing hard and it's really fun to see the smiles on their faces."
Penn State senior linebacker Gerald Hodges was named Big Ten defensive player of the week after his performance against Northwestern. Hodges made a season-high-tying 11 tackles, had a force fumble and broke up two passes.
The Nittany Lions are on a bye week and return to play Oct. 20 at Iowa at 8 p.m.