So....basically some people can type shithead, and others can't? Here's the data on my end at least:
The all lower case Shithead, or shithead, gets censored by these people (data may not be 100% reliable due to fake censorship):
aphex
PHiuR
Saulbadguy
Nitemare
BoomerD
Captante
mh47g
maxster
bctbct
The Boston Dangler
yamadakun
but not these:
OdiN
BlackTigers91
Evadman
newnameman
theprodigalrebel
edit: myself