1) He went on supervised release in 2012, which was to expire in 2017
2) He committed more crimes.
3) He was arrested and tried in 2015 and 2016 and jailed on the new charges in 2016.
The justices made the common sense decision that what mattered was his committing crimes during the period of his supervised release, not whether his sentencing occurred after the expiration of the supervised release.
Thank you for your very concise analysis! I understand it now!
- Megan