For those I respect most, I will always trust the hard choices they make. Viktor chose death. He did not mention it to anyone but me, but the melee was to be his last fight. I wasn't 100% sure he was serious, but I could understand with the Joyful Few massacred why he would feel he had nothing to live for. His men were his family, and without them he was lost. 

The melee was a fight to surrender, and with the onus being on Viktor to declare defeat, he never was going to give. That said, I cannot believe Maelys would do what he did. Aiming for a man's neck in a friendly fight is uncalled for. No one should have been attempting to kill their opponents in melee. This is also partially on him. He is the one who took Viktor's head off, and he bears some responsibility for his death.