New Delhi, Aug. 28 -- There are some purchases you make because you want them, and then there are those you realise you needed only after something goes wrong. For me, a dash cam fell firmly into the second category. I had always thought of it as another car accessory, useful, perhaps, but hardly essential. That changed the day a wrong-side driver smashed into my sedan.

In the chaos that followed, figuring out what actually happened became just as important as dealing with the damage. There were no arguments over whose version of events was right, because my 4K dash cam had already recorded the incident. From the approaching vehicle to the impact, I had a clear video of what happened.

That footage turned out to be more than just a recor...