I believe it's spelled cl_flushentitypacket and I get it sometimes too, very rarely tho. And it appears almost only on very laggy servers like YIS. Try altering your rates, that usually helps for me.
And if he was ON the statue, shouldn't it block his bullets too? They hit me fine. This is a bugged spot and I warned him several times. He even died a couple of times and went back there over and over again, so it's not like he was stuck or anything like that.