I find it hard to believe that Motorcycle Officer Hargis: (1) Left the roadway, (2) Jumped the curb, and (3) rode UP that extended grass embankment and forgot to mention All of this during his WC Testimony or at any point during the next roughly 50 years.
That's more like it but get off the riding up the incline, that's not a necessity for him to be in the RRY for a minute or two on foot. Besides, it's way too steep and he doesn't have to jump the curb like a hero either, he can just get up on it.
I'm telling you, what he did may have inspired Jackson because that's where he and Couch finally got out, west of the underpass and they had plenty of chances to do so before then but chose not to even try.