Oklahoma's Richard Glossip freed on bond after 30 years on death row

>The supreme court ruled last year that prosecutors’ decision to allow a key witness to give testimony they knew to be false violated Glossip’s constitutional right to a fair trial.

Since stuff like this occasionally happens[1], and sometimes needs to be rectified long after a guilty verdict, I don't understand why any state would support the death penalty. Glossip is still alive only because there was a snafu related to the lethal drugs intended to kill him. Had that snafu been overcome, there would be no defendant to retry.

[1] "Occasionally" describes only the cases we know about, of course.