Over-specification is easy to identify as it usually manifests itself in a sentence of the form: ``you must use X because X does Y''. Clearly, a requirements document would be better saying ``you must do Y'', and it could even state ``and X is an alternative way of guaranteeing Y''. Otherwise, if we had a machine that ``uses Z to do Y'' then this machine would be rejected even though it met its requirements.
An example of this is standard 66:
``Open standards shall be used to ensure that the various technical components [...] interoperate''