I was thinking about the girls walking habits. Since Taylor lived on the west side of County Line Rd, I doubt they were in the habit of crossing the street to walk with traffic as folks in the city are taught. I bet they just started walking from their side of the street. So, they would be against traffic, if that is correct.
If a person passed them within minutes of their being shot, (again I don't know how LE can deduce that unless the witness did indeed report seeing another car nearby on one side or the other of the girls) I wonder if they were going north or south.
LE's not mentioning what direction the girls were traveling is interesting. I would think that there would be more traffic going north to south because the interstate is that way (the County Line Rd does cross under I-40, but there is not an exit there), the small community of Bryant is just about 2 miles east on 1120, and Henryetta is to the northeast.
So, I am thinking they left going north, but on the west side of the road, probably more in the middle as indicated. The witness was going north to south and would have gotten a good view of the girls, as the moved over to the edge of the road. He had probably passed the criminals around the bridge either pulled over to the side of the road or he did pass them.
I guess it may be possible that the witness was going south to north though toward the more urban part of that area, I-40, Henryetta, etc. and saw the perps on the other side of the road as they were going south. I wonder if the witness' car spooked the people and they tore off down the road and the girls just scared them.