misconclusion
malobservation
misimplication
misinference
misassumption
false step
misimputation
miscatch
misreckoning
misallegation
misclaim
misprediction
misderive
erroneously
misprove
under the impression
put two and two together and make five
thonk
misconjecture
all hollow
misexpound
misappraisal
misinterpretation
mistakenly
fallacy
fudge
false belief
misfigure
idolum
absurdum
misrelate
misprobe
misapprehend
misexplicate
clear up
miscalculation
miscomprehend
inaccurate
erroneity
thinko
misinfer
misstatement
misknow
not done
wrongly
misassess
misforecast
miscluster
misanalysis
solecism