I came upon a group that was at a similar pace to my own. I kept a distance, many were drafting each other. Mind you, they had blown through a stop sign at full speed, yet were pointing out small hazards on the road. It seemed to diminish my trust for them pointing things out if they completely missed a red octagonal sign universally known. So, bear that in mind when a stranger is pointing out hazards when you're drafting them. They may be missing more important things - your safety - your responsibility. That, and have a good ride. This is supposed to be fun!