Recently digging on the data SE I've found an interesting phenomena. Namely, this.
He has a question and an answer, both with 4 vote count (if it matters: his question has +5/-1, his answer +4/0).
He is not in cage.
On these data, I think his reputation should be 1+5*5-2+4*10 = 66.
Despite that, his reputation is only 1.
His reputation change history seems to show the correct values, although his reputation graph shows a third value (rep 81, with a small decrease around early Januar to 79):
Why is it so? What could affect his reputation out of these?
(P.s. I don't know anything from him, I found his page by some data SE digging.)