In the near vicinity, were a few workers that does assembly work from the harbor to the warehouse and vice versa depending on the supplies needed to deport out or into the warehouse. Miles couldn't act rashly since there were a few people nearby, so he continued to observe and wait for an opportunity. If he acted now, he'll be noticed. Knowing there was bound to be a break time in between, he waited for the right time to strike. Thus, he waited for the opportunity to get Chao and Rush back with him alive per Su Na's order.
As predicted, shortly later, was the last break time. Chao and Rush went to the warehouse for a smoke break. They were responsible for transportation and not manufacturing. It seemed that not far from the area were the manufacturing plants on the farther side. Some people's duties were to oversee the supplies from the manufactures to the warehouse, while some people were assigned to transportation from the warehouse to the cargo ships.