you re right there - he has to leave for 4 hours. the rule is very clear about it, and it surprises me how much ppl interprete into rules that leave absolutely no room for interpretation. - it says, when you die, you leave the winner and the system. - i don t see any room there for interpretations....
not 100% sure - but i think that even a guard system owner must leave his guard system when he was killed there by an invading enemy.