To be fair to Max he had (and likely still has) an extremely busy schedule which likely caused him to overlook some things and prevented him from having more time to dig through online archives or contact eyewitnesses to these vents. Even Grazulis doesn't mention extreme scouring or vegetation from this tornado, although when you're compiling information on 12,000+ tornadoes you're bound to miss some things and not have time to fill in every single detail.
That detail about the Beaver Falls tornado, if true, might be a record as the official record for longest distance of a person being thrown from a tornado is Matt Suter of Fordland, Missouri who was carried 1,307 feet (13 ft. shy of a quarter mile) and lived to tell about it.
Sources about Matt Suter:
1.
https://www.guinnessworldrecords.com/world-records/furthest-distance-survived-in-a-tornado-
2.
I've heard of Matt's story before and it is truly incredible. A similar event that I can't find much information on is the teenagers who were apparently thrown 1,000 yards by the Brownwood, TX of F5 of 1976 (likely an F4 in actuality) and survived. Kyson Stowell of Castalian Springs, TN from the 2008 Super Outbreak also comes to mind.