That's true, but it takes more than one example of confusion to justify the label "ambiguous." Otherwise the label would have no meaning; it could be applied to anything that had ever caused anybody confusion, which is everything.

For example, the meaning of the word "ambiguous" is not ambiguous. If somebody were to ask what the word meant because they did not know the definition, it wouldn't make the word's meaning ambiguous. It would make that person uninformed.

Confusion due to a lack of awareness of an unambiguous standard is not synonymous with ambiguity.