Yes, he had walked in moments before. And he had to say he was amused by her attempted to cast the spell. He could see several things wrong at first, but he decided it was best to keep his mouth shut when she turned on him and started yelling. Honestly, Greg thought her biggest problem was being to tense, to worried about the whole situation. But getting Pansy Parkinson to calm down and think rationally was not a skill he had yet mastered.
"One, they are not going to suck your soul out. I wouldn't let it happen and neither would anyone else except maybe Umbridge. Two, relax. There's no point in trying if you can't just calm down and clear your mind. Your biggest problem is worrying to much about casting it." He walked forward and pulled out his wand and took a deep breath before yelling Expecto Patronum. A giant, hulking figure shot out of his wand and exploded into the room, shaking it somewhat. Yes, he felt safe when he casted his Patronus in particular. With a wave of his wand, it disappeared. "What memory are you thinking of?" he questioned.