[dm2]

Your scenario is very possible and was my initial thought as well. The call dropping could be carrier/phone/region specific due to invalid or error causing commands breaking something when the call logging or recording is activated. (tower connection, phone software, phone radio firmware, or anything else along the connection)

It's probably been fixed by now if it was a bug such as that. I'm sure bugs like this go unnoticed every day by people interacting with computer systems and just brush it off as a "glitch" or "service issue".