As I understand it, they did not say that there was a constitutional right to engage in sodomy. The existing law violated due process, they said, and presumably there is some process by which sodomy can be illegalized, although they neglected to explain what it was.
The holding of the case is that there is a constitutional right to engage in Sodomy. The reasoning of the case--such as it was--avoided such direct statements, probably because it would make them sound stupid.
They pretty much said there was a constitutional right to engage in sodomy.
As per Wiki