Well then at best the phrasing in the article is terrible, since it explicitly says they voted to end his life.
I note that Wikipedia writes this[1] about felony murder in the US:
When the government seeks to impose the death penalty on someone convicted of felony murder, the Eighth Amendment has been interpreted so as to impose additional limitations on the state power. The death penalty may not be imposed if the defendant is merely a minor participant and did not actually kill or intend to kill. However, the death penalty may be imposed if the defendant is a major participant in the underlying felony and exhibits extreme indifference to human life.
Thus it would appear as if the prosecution successfully argued that he was a major participant, and that's what the jurors are regretting?
[1]: https://en.wikipedia.org/wiki/Felony_murder_rule#United_Stat...
