Greg's immediate response to someone falling on top of him was to go for his wand, shifting into a more offensive position in case he needed to hex someone. He glanced around, taking in the sprawled figure but disregarding it as unthreatening until after he'd checked the rest of his surroundings. A few people had paused, obviously noticing the accident, but Greg's glare encouraged them to put their wands away and hurry on. Satisfied that no one was pointing a wand in his direction, or likely to shove anything further at him, he lowered his knees to the ground and turned to the body beside him.
"I'm fine," he muttered. It would take more than this to actually hurt him, though he could feel a slight ache in his side where one of Merwyn's shoes must have caught him just under the ribs as he went over. "You?" He didn't get up immediately - wanting to make sure the stranger wasn't badly injured. He spotted the sunglasses a little way away and reached for them before anyone could step on them. "Need these?"