Dusty's eyes opened wide when he saw that Tracer had somehow mutated into a large Russian guy with tattoos, and was rushing out the washrooms brandishing a lethal-looking gun. His eyes opened even wider when he realized that Tracer had NOT gone in with snake tattoos all over her face, and that this Russian dude was probably out to kill him, obviously. Uh-oh.
Dusty yelled," Expelliarmus!" and then posed grandly with a smug smile on his face, pleased at his own wit. Then, when he realized that he wasn't living in the world of Harry Potter, and the gun wasn't flying into his waiting hands, he turned and ran.
He dashed through the airport, pushing away squealing ladies and whimpering men alike. Adrenalin pumped through his system as he searched for a place to hide, and finally settled on a giant-sized woman who obviously wasn't going anywhere without help, which she wasn't getting anyway. He dived behind the woman and effectively got lost in her monstrous behind.
The plan worked, as Dusty assumed, as he quite obviously wasn't dead. All limbs in working order? Yep, he definitely was still alive. Wonderful. The Russian dude seemed to have vanished, running around in a different part of the airport, probably.
He then crawled out from the woman's bottom and went to check on Tracy. There she was, inside the women's washroom, swimming in (quite) some blood. He was just about to take a bite from her chewing gum, which had fallen out of her mouth in the process of instructing the Russian guy to the men's washroom,, when he heard a shout from behind him. "This is ladies', boy!" Dustin stared at her for a few seconds, uncomprehending, before popping the gum into his mouth and dragging Tracer out of there.