This kind of lines up with what I think may have been his escape. All I know about GH's suspicious man claim from a witness is the person claimed they saw the individual from the kitchen window of a residence along C.R. 300. I have no idea which residence this might be, the M family live across the road, and the old house they own (rental property being rehabbed at the time of the murders, IIRC), would likely obscure some of their view of 930. I'm going off of Google Satellite and my drive through there.
So that leaves residences further east on C.R. 300, adjacent to and east of RL's property, which I find highly unlikely. By that I mean I find it highly unlikely someone unknown to people along C.R. 300 would be walking east of the cemetery and the drop off point for A&L, and not be recognized.
I've pondered three ways BG may have fled the murder scene:
1. Through the woods, which would be the M property in the gorge, and then to the trail which leads to the MHB. He crosses paths with a witness or witnesses while walking to the former CPS property.
OR
2. He heads up the trail which heads west of the abandoned gravel pit, and up to the perimeter of the M parcel which is farm land on the south side of C.R. 300, again eventually ending up near the trailhead closest to the drop off point. He could have kept to the tree line, in which case I see it is possible someone on the M property looked out a window and saw him across their field. In this case, he would have gotten back on the main trail near to the outbuildings the M family has on that property, the ones right by the main trail and the trailhead for the nature reserve trail, mere feet from the drop off point/parking area and the park bench.
OR
3. Cemetery to C.R. 300, walks to the drop off point area, and gets back on the main trail on the way to FB. I find this highly unlikely, but I've seen that theory batted around, here.
JMO
-FD