I'm not sure how the law applies to the present case. The improbably named decedent's death was caused by the intended victim of the attempted "robbery in any degree". Is the intended victim a "partcipant" as intended in the law?
That's a question for lawyers, and
IANAL
I don’t think it makes any difference who killed whom, just that there was a death during the commission of the felony, even if it’s done by the victim, the other participants are guilty of aiding in the killing that would not have happened if they were not there.......
God forbid that common sense be applied.