If you're on Windows 10 you can use the Game Bar to shadow record say the previous 30 seconds of the game. Then you go to Game Bar, select "Record that" (it looks like a repeat icon on a music player, not the big red circle). You now have the last 30 seconds saved as a video. Hopefully that will help. I've never PvP'd so I can't check the nuances of how the gamemode works, but hopefully that'll help.
