I just found out this by an accident. I was trying to stop a warrior to return the flag, so in the last second few yards before the turning point as an act of desperation i blinded him. I couldn't kill him or do anything, cause there were 4 enemies around me who killed me almost instantly. The point is that when the warrior was blinded he moved few times through the flag return point. After the blind was over he wasn't able to return the flag no matter how much times he went through the return node. Anyways, at the end he dropped the flag, took it again and returned it xD I guess someone might find this usefull ^^