In the event screenshotted below, it looks like there are two related problems. First, it shows no skill/stat that affects the roll -- as far as I've seen, Diplomacy/Charisma should be modifying rolls like this. And second, I reloaded and re-played the event several times, and the result is always 97 -- even if I give the Foreign Affairs director a +10 charisma medal right before making the event decision.
So it looks like it's using a constant -- if it was a predetermined roll, it would at least apply the addition charisma +10 modifier that I just added, I would think.
Also, I noticed that Mind +3 doesn't happen like the first screen said it would.

