I had a creature with trample, my opponent had a 2/2 lifelink
I attacked and they blocked with their creature
My damage brought them to -1 as it killed their creature and then the excess damage hit them
They then lost the game but at the same time they healed to +1 health, this should have activated at the same time as the damage and should have not counted as a death for my opponent as it should have all happened at once.