Well here is a case of being distracted or having tunnel vision, either case this is one more thing about playing music in your head phones, and like the man says it only takes a second. Just MHO
I installed two rear view mirrors and a back up alarm on my B2601 with BH, the mirrors help me and the alarm warns others. I have also instructed the wife not to approach from behind on any equipment I am operating. However I know that I am solely responsible for others safety.