Medighost and I were the only ones who stayed the entire mission, so the damage for every player slot except for the last was reset. However, the Engie and I were also the main damage-dealers throughout the entire mission. The damage shown in the screenshot for the both of us is for the last two waves only. Our damage before that was: https://steamhost.cn/steamcommunity_com/profiles/76561198059887323/screenshot/545263034560063653

Post-reset Wave 6: https://steamhost.cn/steamcommunity_com/profiles/76561198059887323/screenshot/545263034560206487

I'd estimate that there is less than 20,000 damage missing from the final scoreboard that didn't belong to either the Engie or me, and I did over 20,000 more than any other single player over the last two waves.