" in some foreign language" is indeed irrelevant, I don't believe the "some dude yelling" (talking) is however. I've read different studies that suggest talking on the phone even while using bluetooth is severely distracting for the driver.

Andedotally, I've been in cars with taxi drivers who were on the phone when I got in and talked for the entire ride, whilst navigating a city traffic, while also looking at their gps to work out where I needed to go. I did not feel safe in the slightest.

If it ever happens again I'd like to think I could ask them in a polite way to end the conversation or exit the cab, but how?