The reason why he fled the scene was not only because of the beetles, but also because of the gunshots that were fired by the soldiers under panic. There was one more reason too—the gene-altered soldiers might be able to get rid of the beetles soon.
After all, the predators that he lured there weren’t the superior ones. His biggest threat, the gene-altered soldiers, was only troubled without incurring any actual damage. That’s why he decisively ran as fast he could. Chang wasn’t a matching opponent for any of those soldiers once they got away from the beetles. The gene-altered soldiers were superior in speed, and Chang would never be capable of outcompeting that. His only advantage was his high familiarity with the jungle and a deep understanding of the nature of the predators that lived within it. He knew those things by heart, and now, was able to utilize his knowledge to defend himself.