That is not how Felony Murder works:
Miller was there, did he drive those others there?
If people rob a bank and the driver sits in the car and never enters, but those that do go in and end up killing someone then all those involved are charged with Felony Murder regardless. So if Miller got the gun for the guy and drove him there then he is subject to charges also.
UGA Jalen Carter left scene of fatal accident involving Devin Willock
https://www.youtube.com/watch?v=8b39104sveU