To give you some thoughts (as I was telling you to post on a generic community, note that if I played some shadowrun v3 and a lot of cyberpunk 2020 a while ago, I am not a shadowrun guru)
My scenario-writing tip is to write down what happened, who is inlvolved, why and so on. Looks like you've done most of the work here. You know that some person are on corporate oil rid and want environmental activists to take the blame.
Based on that information, and on the fact that shadowrun is a cyberpunk game, and you need to keep the punk inside, meaning corpo are evil, environmental activists are the good guys (and never thrust a dragon). you don't want the environmental activists involved at first, you want the player to find out that it's a case between corpo where they find-out that the good guys are the victim. Letting more room for a moral dilemna for the PC. Do they want to let the world know the truth with the risk to get in trouble with the corpos an law. or do they want to protect themselves by repeating the narrative about bad environmental activists who are just eco-terrorists ?