Correlation, causation, something, something.
So while it's not correct to say Cicconetti's approach lowers recidivism, or that jail time increases it, it's definitely correct to say that a punitive, jail-heavy approach to justice is not at all effective at rehabilitation.
That's not true as well, see Friedman's Thermostat for the extreme case
Generally rehabilitation percentages for "alternative punishments" can be misleading because they tend to be applied to situations where they're more likely to succeed
Thanks for bringing up Friedman's Thermostat, I wasn't aware of that thought experiment, and it's a really great example.