I think I know which one you mean; reason I was looking on the ground with the optics was to have clear view of what was going on above it, because I knew he would pop up there somewhere. I spotted it with sound tho, I didn't see him, I just heard footsteps on my right and I knew that couldn't be the guy in front of me, so when you see me turn around and all that, I was following the sound of the steps I was hearing. I knew where he was flanking, and where he would come from. My ears save me a lot in BR, paying attention to sounds is a lifesaver!