Foam Padding on Mobo?

Equipment Proton Packs
1

So I was watching GB 1 last night, and in the rooftop scenes, I noticed a weird shadow on Venkman’s motherboard. It looked as though there was a strip of something along the top edge of the mobo, so I hopped onto here and found these:

http://www.gbfans.com/images/equipment/reference/1/5.jpg

http://www.gbfans.com/images/equipment/reference/1/17.jpg

Does anyone know the story on this? I’m guessing one of the actors nailed the back of their head on the mobo or something and it was added somewhere in the middle of filming?

2

Running with the proton pack I found that the pack bounces and the exact place where there’s foam on the mobo is where it strikes the back of my head. There is in fact a strip of foam there, and it is for the actor’s protection.