[squarefoot]

Seems to me like it's ignoring context and indirectly applying literal synonyms in the wrong direction. That is, if screwing->fucking (sorry, it's necessary to make the point) but not the other way around except in one context and screwing can be synonym for tighten something in another context, then bracing->tighten and tighten->screwing, it could have "walked backwards" doing something like brace->tighten->screw->fuck, where the last synonym is not valid in the context where the first synonym could be.

Sorry about language and the poor description; I seem to have an idea of the problem, but it's not my field and have no way of describing it in formal way.