Yes, Rob isn't very well known, is relatively new to the sport, and hasn't done any of the more recognized events. Despite that, Rob is the real deal and quite a good runner. Last year alone, Rob won the Race Across USA 2015, and completed over 1 full year of at least one marathon per day. Here are some links about the Race Across USA that he won. (Incidentally, I was an "Advisor" for that race.")https://www.facebook.com/RaceAcrossUSA/http://raceacrossusa.org/http://raceacrossusa.org/results/http://raceacrossusa.org/advisors/
Personally, I have met Rob twice, and I spent 5 days watching him run last year's Race Across USA. I crewed and advised the race for its first 5 days in New Mexico. By far, he was the class of the race, and had no challengers for any of the days I was out there. The race format was to run 26.2 miles per day with one day off per week. On that day off, Rob still went out and ran 26.2 miles to keep his consecutive streak alive.
While running 26.2 miles per day is not the same as averaging 70 miles per day, I am perfectly content that Rob has the physical and mental ability to achieve this, and a great chance to set a new record.
By the way, many of Rob's competitors from last year's race are helping him with his record attempt including but not limited to Nancy Bennett, Newton Baker, and Bryce Carlson. Nancy has already done an 80 mile day with Rob that was posted on Facebook. Also ESPN has been out with Rob taping parts of his record attempt.