What does "Benefit of a second's distance" mean
I suspect it’s the distance a vehicle travels in one second, and here just means with even a little perspective one could notice the issue.
The "Rule of Seconds" How can we determine whether the truck behind us is following too close and what can we do about it? That's where the "rule of seconds" applies. At highway speeds, say 60 miles per hour, a vehicle is traveling about 88 feet per second. Most commercial truck drivers are taught to allow one second’s worth of travel distance per ten feet of the length of their truck, plus one extra second for safety, between themselves and the vehicle in front of them. - http://www.allenandallen.com/blog/the-rule-of-seconds.html