“every last person involved is GUILTY of Murder”
Doubt it. There is a difference between being a knowing accomplice and MAYBE having rendered insufficient care. And arresting someone is not an inherently deadly behavior.
“the rationale underlying the felony murder rule is that certain crimes are so dangerous that society wants to deter individuals from engaging in them altogether.” That doesn’t describe an arrest.
It might describe a baseless traffic stop and feckless non-immobilization done as a pretext to scare the kid witless, prompt him to run for his life, start a foot chase, and give the police an excuse to begin a premeditated six-on-one beatdown.
If it was a pretextual stop motivated by personal animus, then the stop itself was illegal and there’s your felony to fulfill the felony murder rule.