Zoom in on 2:48, guy in helmet pursuing them with right arm outstretched.

In this video from another angle you see the third person running after them and if you watch closely it looks like he is holding a gun that he cocks right before the first shot rings out: https://youtu.be/ss-G-FX3Nys?t=14340

spez UPDATE/CORRECTION: This thread shows where the first shot came from. What I was seeing is a reflection of this on the black car. Actual muzzle flash can be seen in this video

Zoom in on 2:48, guy in helmet pursuing them with right arm outstretched.

In this video from another angle you see the third person running after them and if you watch closely it looks like he is holding a gun that he cocks right before the first shot rings out: https://youtu.be/ss-G-FX3Nys?t=14340