Driver tells the other guy to contact two people, which he texts them - you can clearly see that in the inside dashcam (kudos to that guy - not sure I could have typed a text while all that was going on).
From the follow up article we now know those two other people they contacted were not in the escort car as most of us assumed, but were in fact another armored car crew that left at the same time and were part of the same cash/valuables transfer. The driver was concerned that would also ambush the other crew and giving them a heads up.
Honestly, what would the point been of calling the cops? This would all be over in a few minutes either way. Waste of effort. And yeah, for all we know there was a panic button that was pressed to at least let HQ know they were in trouble.
The driver is a former police special forces sniper, and trains law enforcement how to shoot. I think these guys had everything under control. As the Task & Purpose article mentioned, he did exactly the right thing: He got out of the kill box (ambush) and then setup his own. The bad guys just weren't expecting any major resistance.
- "Great spirits have always encountered violent opposition from mediocre minds." - Albert Einstein