Hello,
when I win a match and a grenade was launched before victory, this kill me and in scoreboard calculate this death.

Lol. I was holding an incen grenade, I pressed and held the left click, setting up for a throw. Then the game ended and during the victory screen I said "fk it, lets burn baby burn!" so I pressed the right click and held the nade. Few seconds later, I exploded into a celebratory inferno during the victory screen, it was so funny. The only thing you could hear during the victory screen was my character's screams as he burned. Rip.