Possible evidence tampering of Amtrak 91 crash caught on camera

Tampering with evidence can be any action that destroys, alters, conceals, or falsifies any sort of evidence.
While looking at all the photos of the crash I came across this one. There are several photos taken from this angle through out the day. This photo shows the FRA, NTSB and FBI later in the day.
www.metro.us/sites/default/files/styles/gallery_landscape_zoom/adaptive-image/public/main/articles/2018/02/04/LYNXMPEE130EC_21.jpg
Nothing out of the ordinary there. They are there to investigate the crash.
Another search also reveals there are several photos of these two railroad personnel, a man and women wearing hardhats, that identify them as CSX personnel. Nothing unusual about that. Their railroad. Their crash scene. Now are they part of any official investigation? I do not believe they are because they are not the NTSB, FRA or FBI.
Ok. So when you look at the next photo I linked, you ask yourself, what’s the big deal? Well I tell you.
The photo shows the two railroad personnel with their backs turned while another person appears to be tampering with the switching mechanism before ‘official’ investigators arrive at the scene. If this person is part of the ‘official’ investigation, then why are the two railroad personnel not witnessing what that person bent over is doing? Why do the have their backs turned? Are they the lookouts to make sure nobody else is witnessing what is taking place?
localtvwjw.files.wordpress.com/2018/02/gettyimages-914190130.jpg?quality=85&strip=all&w=770
You decide.
 
AC