Just about to say something else to Olivia, she was cut off by the fact that someone had their hands on her. She turned around to see a guy she didn't know at all trying to manhandle her, though it didn't take a genius to figure out that this was bad with a capital B. Even if Olivia hadn't known him, Felicity had told her that she'd keep her safe, and that's what she was going to do.
Spotting the gun, with wide eyes and full of fear she let him yank on Olivia down into the alley, having no choice really but to follow. She wasn't just going to let Olivia go, not like that. "Leave her alone, she hasn't done a thing to you." she protested, reaching around to see if she could put herself in between Olivia and the man she didn't know.