They are two completely and utterly separate subjects.

His 'twatiness', has nothing to do with stealing off him.

Anyone trying to conflate the two is just trying to find morale high ground for a justification of an immoral act...

'Conflaters' are twats to. (and a much more vicious breed of twat, I might add...)
' They're all twats', as you said so succinctly, previously!