So trying to read the 2HG format rules, and i'm not sure i understood how does it works.
Any team has a shared life pool starting from 30. Any damage to a player is taken from the shared hp, so when it reach 0 the team lose the game.
But the damage is dealt to a single player. So there could be a case where the team lose the game even if the shared health pool is not zero (excluding special cards).
For example: if Team A cast a card that says i.e. "Deal 10 damage to target player", and now the team B has 20 life points. Team A deals 10 damages to player 1 in Team B, and he can't block this action (neither is teammate), it means that since the single player life is the (total life)/2 = 10 Player 1 of Team B reach 0 and then the team lose the game.