If a skill or ability roll is of the "you fail, you die" sort, it behooves the well-prepared GM to offer another last-ditch attempt on the off chance (i.e. inevitably) that the first roll fails. The important thing is to make the second chance make sense within the parameters of the scene.
Another important thing to make sure of is that succeeding on the last-ditch chance isn't as good as succeeding on the first chance.
If someone might fall, they get a first chance to hold on or regain balance and remain relatively ready for action, and a last chance to grab something by flailing their arms out and ending up dangling over a chasm. If someone is potentially exposed to a poison, they get a first chance to avoid ingesting it or having it get into their bloodstream, and a last chance to tough out the effects and just be sick for a few days rather than die. If someone triggers a deadfall trap that collapses the ceiling, they get a first chance to jump clear and avoid the rubble, and a last chance to crouch into a ball and end up slightly wounded but trapped.
There are degrees of success, and if you need to throw a character a lifeline, make sure the success only just saves them, and inconveniences them in some other way. (And, as always, throwing them a lifeline should be used mostly if the situation and the failure are just dumb luck, not if they've ignored warning signs and done something suicidally stupid anyway.)
[Reminder: Our guest commentators have not seen Rogue One. Part of the fun is seeing how their untainted impressions re-interpret the movie through the lens of our comic.]
I think I'm starting to see a pattern here.
You have a chance to save your character. Just grab the railing and drop the weapon.
You have a chance to save your character. Your loyal followers are willing to carry your otherwise immobilized body out of the stronghold before it is destroyed.
You have a chance to save your character. Just provide him with some information, and he won't Force choke you.
Would Darth Maul have been willing to help pull him up out of the pit? That would make 4 for 4 in 4 sessions.
Now, there was a fifth character. But that character apparently died in a horrible offscreen tragedy, and we don't know the details. But you have to wonder: does Jim have a desire to prove the adage of "you might stop me, but you'll never stop my rerolling!".
But when all is said and done, Jim will take 3 rounds, and take advantage of "thinking is a free action", to try to figure out some way to survive without having to drop that blaster.
Now, has the transmission been stopped? We've pretty much been told that everyone is going to die, and that the plans are safely transmitted. The terminal with the data crystal has been destroyed, all controls for the transmission have been destroyed, and it's reasonable to assume that the dish's direction has been altered, or blown off entirely.
Therefore, we can assume that it has been safely transmitted by GM fiat/plot magic.
GM: The railing gives you +4 for each hand you use.
Bria: I grab the railing! 8!
GM: Okay, you...
GM: Are you still holding your blaster?
Bria: Of course!
GM: You fail and start sliding down the collapsing catwalk.
Bria: Uh oh.
GM: You have a last ditch chance to grab the railing before you plummet to your doom.
Bria: Hmmm. How high up am I?
GM: 828 metres. Do you want to drop your blaster?
Bria: Let me think. If I fall, I'll have... about 18 seconds to decide what to do next.