Shot by the Victim

Four men held up a jewelry store. The owner and an employee fought back. One robber opened fire and the owner fired back. The owner was killed, and so was one of the robbers, shot by the owner. A surviving robber was charged with two counts of murder: one for the owner, and one for his own accomplice, who died from the owner's bullet. Your vote is on the second count. Felony murder makes a robber answer for a death his robbery causes. Does that reach an accomplice killed by the victim fighting back?