In California (and other so-called "agency" jurisdictions), the felony murder rule only operates when the felon commits the murder during the course of the felony. (In other states, any death that occurs during the commission of the felony can be charged to the felon.) To see the difference, consider a robbery, where one of the victims shoots one of the robbers, or where a police officer accidentally shoots a bystander. In California, the [remaining] robbers couldn't be charged with murder under the felony murder rule, but in some other states, they could.
Anyway, fast forward to 1969: Taylor is the getaway driver for a couple of guys who are going to rob Jax Liquor Store, operated by Mr. and Mrs. West. The robbers go in (armed) and one of them "chatters insanely" during the robbery: "Put the money in the bag! Put the money in the bag! Put the money in the bag! Dont move or I'll blow your head off! He's got a gun! He's got a gun! Don't move or we'l have an execution right here." And so on.
Mrs. West, who was up on a ladder somewhere in the store, pulled out her gun and started shooting, then Mr. West got off a few rounds. When the smoke cleared, Mrs. West had plugged the robber who hadn't been "chattering insanely."
Can Taylor, who was sitting out in the car the whole time, get popped for first-degree murder? Not under the felony murder rule in California, because the death was caused by Mrs. West.
Never underestimate a determined jurist, though. Justice Burke, who dissented in the case that said the FMR doesn't apply when a felon doesn't do the killing (People v. Washington, 402 P.2d 130), comes back with this gem:
The robber's "insane chatter" was "sufficiently provocative of lethal resistance to support a finding of implied malice." Therefore, since robbery is listed in the murder-1 statute, the getaway driver can be charged with first-degree murder.
So now, in California, a felon (or his accomplice) can be charged with murder when his conduct is "sufficiently provocative of lethal resistance" and somebody dies, no matter who the decedent is or who kills him -- except, of course, when the decedent is the one whose conduct was provocative.