Would this man's eyes have seen something where theirs had been blind? 
Their perception of the situation may have been faulty; could this man have detected something they did not?
The man was the only one who didn't see what was going on.
When you think about it that is not at all how it happens in the offline world.
A man stands in front of a torn down building.
A young boy is outside.
a man wearing high heels
He shouldn't have been trying to slit her throat.
Isn't there never?