mismanager
obviator
deplorer
misreporter
disclaimant
shunner
scornee
discounter
disfigurer
disregarder
misjudger
obscurant
reprobater
misbehaver
misreader
contradicter
reprover
rubbisher
disagreer
dichotomist
ridiculer
disclaimer
distorter
antialarmist
disheartener
discommender
overpredictor
fulminator
abnegator
jeerleader
miscegenist
insensate
confounder
disenfranchiser
miscegenationist
disobliger
quasher
dissatisfier
dismayer
reclaimant
disrespecter
discourager
disendower
refounder
Monday-morning quarterback
scorner
distruster
doubter
denier
abhorrer