Heaven on High conseal

[Fawkes]

The player went directly infront of it and it aggrod in that video. Serverlags/ticks makes it look like the player is only behind the mob shortly before, but it passed its center for a brief moment. Also when the player moved earlier close infront of him, the mob turned. When a mob turns he won't aggro, for some reason, until it turned fully. I'm pretty sure it would aggro if you would stand at his ring at the arrow that shows its front.

The player walks back and forth in front of it from 0:16 to 0:30 and it does not aggro.