My take, cynical at the root - unfortunately, is that "heads I win, tails somebody else loses" defines the low end of the premise; whereas the 100 years (times 5 for a good measure) defines the utter waste of the idea of rehabilitation.
How could he stash billions when the bankruptcy estate tracked everything? That would be like the FBI overlooking Silk Road coins. There would be an obvious hole in the account records were he stashed it. Everything is traced via blockchain.
Quick opinion:
> sentence of 63 to 78 months
No, too short.
> which recommends a sentence of 100 years in prison
Um, too long.