Good story, but two points strike me as odd. How did they record the call? I wouldn't even know how to do that on my phone. Also, does Russia have such good cellphone coverage, even in areas where bears live?
Yes, Russia is not the US. Cell coverage is excellent, even outside cities. If you get deep into the Taiga of course there will be no coverage, but in this case the camping ground was not too far outside a city of 200,000 people.
Almost all the cheap Chinese phones, such as Xiaomi, come with call recorder built in. My exwife has one, for better or worse, I need to be careful what I say!