Had a very similar experience
I was driving around 2am one night and was almost smacked by a drunk driver. I called the cops and followed him. The ONLY thing that saved me from suffering a similar fate as our protagonists was that I made the split second decision to just go ahead and stay on the phone. Looking back on it, this helped them know exactly where we were in real-time. They caught up to us after like 2 or 3 minutes. Did I dodge a bullet? Probably. If he just made a turn onto a different road, thus rendering our earlier location irrelevant, would I be dead? I think you know the answer to that.