But that's the question. The probability is not 0%. It may be %0.01, or %0.001. Can either of us find any existing cases where a defendant with Aaron's background received a 33-level sentence increase? I would propose that that has never happened in cases with similar circumstances to Aaron's. If you can find one, I'd be interested in the citation.
In the absence of any examples, my argument is that the chance of a 35 year sentence is not functionally different from 0%, and Aaron (and any other defendant in this situation) should have made decisions based on the 99% of sentences they were actually likely to receive.
One last note: you mentioned playing Russian Roulette at those odds. Russian Roulette normally has a 16% chance of death. I wouldn't play RR at 16% odds. Would I play it a 0.001% odds? Probably, presuming the benefits of playing RR were of significant value to me.
Aaron's chance of a 35 year sentence was not 16%. It was also not 0.0%. It's somewhere in-between, and unless you have evidence that shows otherwise, I'd personally guess it was below 0.01%, and his choice of suicide remains a tragic one. YMMV.