Well I like to think it is at least well-reasoned supposition. But if our dear author wants weigh in she can always do so, of course.
By the way let me tell you how I think Renaldt's trial will go:
Since Hannah hasn’t told us anything specifically about the legal system I’m loosely basing this of off a mixture of the British one and what I know from legal history about the late Austro-Hungarian one.
First off her lawyers are likely going to succeed pinning the (second degree) murder of Gaspard entirely on the corrupt forewoman who was her partner as only Blaise and some lowly miners were witnesses to that as my mc and mr. Blanchard weren’t yet there. So, bam, poor Auguste won’t legally be the child of a killer.
The slavery and racketeering charges are ones she won’t really be able to weasel her way out of, but dishearteningly I think even that will be mostly due to the fact she kidnapped and indentured my mc after he was already officially engaged to the prince, which means the judges cannot afford to let her off lightly there without risking the kind of diplomatic incident where the Westerlin Royal family would have to publicly apologise to the Zaledo royals, now including my mc. No matter what compromat she may still have on some judges and politicians they probably won’t dare risk that. And Renaldt probably won’t risk her child getting on the shit list of the Westerlin royals as that really would mean Auguste would be royally fucked and won’t really have a chance to rebuilt his reputation or land on his feet.
Now that is for my main mc, assuming the Prince and the Zaledo royal family continue to back him. For other mc’s this part may also go considerably worse and I can see the charges either getting reduced to “involuntary deprivation of liberty” or the judges taking advantage of the fact that while slavery is illegal it was in almost all European justice systems a crime hardly anyone was ever convicted of and it therefore did not carry an enumerated (minimum) punishment, which means this is the time to use what blackmail and compromat she still has left to get the Court to exercise its “judicial discretion” to reduce the sentence to a slap on the wrist “punishment”.
The only thing she won’t really be able to weasel out of is the (inheritance) fraud and even there it is likely that part of the blame and shame will be shifted (rightfully) to Gaspard’s uncle, Blaise’s aunt and (wrongfully) the mc’s parents.
Either way the mc, Blaise and mr. Blanchard/miss Dalca are going to have to go through a round of re-victimisation as public witnesses in front of a hostile Court. So, yes, he won’t have much sympathy for “poor” Auguste. Neither will Blaise, I would imagine.
So, yes, this means that for any mc who did not get officially engaged to Rosario, like my main one, her crimes are mostly going to get reduced to the same sort of thing the mc’s parents did, essentially fraud.
Auguste will also always have one thing the mc never had to help in rebuilding his fortune, if perhaps not quite his reputation, he remains a titled aristocrat and in a few years, after the news cycle has well and truly moved on, this alone makes him a desirable catch to wealthy industrialists who want their kids to “marry up” and get a title. And if he does not want to do that it is extremely likely he can still get into the sort of relatively cushy upper middle class job I mentioned earlier, by then at least.
Sure, just one final note, having finally played my way to an Auguste ending, Auguste it seems will have far more support than the mc ever had as Freddie, Hartmann and his Aunt, Sidonie seem to be his true friends, no matter what, and won’t ever drop him. Needless to say Hartmann and his Aunt are wealthy enough that he probably has to give up very little in financial terms and could even continue a life of luxury. 
Fortunately in Auguste’s case we do get the only sort of angry, stressed or upset response to the events in the entire epilogue and the mc can choose to dump them over it.
