Rule of zero article
Solution 1:
It's condensed language - I feel it is broadly correct - he is saying "we are yet to obtain review for compliance with German law". Both sound a bit clumsy - the latter would be intelligible to an outsider, whilst what your executive wrote would be intelligible only to those who knew the context. Here "review" (rather than "a ... review" or "the ... review") could be one response or more than one response, I would say it is a category of response rather than saying whether you are getting one or more response.