It's true that Pastoors was more involved in handling contract negotiations while Demoff was largely focused on The Move.
However...
It's hard for me to believe that Demoff and Pastoors couldn't find a few minutes here and there to discuss each contract situation as it arose. That's executive management 101.
Bottom line is that they set a ceiling for what they would pay Jenkins. Turns out that it was too low to get the job done. Would've happened whether there was a move or no move. They would love to have a do over, I'm sure.
Turns out it created a cascade of annual tagging for the services of TruJo that's still affecting the Rams this season.
But all the above doesn't change the fact that Demoff is responsible for handling contract negotiations and terms. Snead is the one responsible for talent evals. The HC is the one that tells Demoff which players are desired.
Sometimes errors occur.
The following is my take...
Contract extension for Tavon. Pretty sure that''s on Fisher.
Trade down with Bears in '12 costing us Bobby Wagner. Pretty sure that's on Snead.
Failed negotiation with JJ resulting from setting the ceiling too low. Pretty sure that's on Demoff (Move was no excuse).
All teams make their fair share of mistakes. Even the best of them. My examples here are just to illustrate that all 3 facets can and sometimes will make mistakes. And that those mistakes can be VERY costly. The trick is to minimize such mistakes.