Help on Prince of Persia: Warrior Within PS2 GLITCH?

I am playing Prince of Persia:Warrior Within, and at the sacrificial altar, after killing Shahdee, I went through the portaI to the present and then back to the past, got a cutscene of the prince looking down on the empress and shahdee arguing and then himself walking in, I then somehow got a glitch which meant that he turned invisible except for his head and sword, and then I died and when I pressed retry, he was the sandwraith. What did I do wrong?