Hmm, window of opportunity to kill the only witness. Hope he has more guns of his own.
The sad truth is that this agent is going to be fighting an uphill battle to try and prove that everyone he shot was endangering his life. If the crooks were in their car his vehicle was no longer in danger and you’re dealing with a property crime. He’s going to have to prove that he is proficient with the handgun he used and will probably get sued for shooting anyone other than the driver that was threatening his life with the vehicle.
I'm sure there are several cops in the area headed that way with an extra if he needs one.