This web page has published what they claim to be a full transcript of the ATC/pilot conversation:
https://meduza.io/en/news/2021/05/25...nsk-dispatcher (look for "read more")
I copied the transcript here to make it easier:
https://eslweb.epfl.ch/cgi-bin/newsa...view=1&id=2383
The pilot seems really sceptical, keeps asking where the information is coming from. He asks what level of alarm is being raised, and when ATC says "red" he finally agrees to divert to Minsk.