@Mike Duggan : Your colleague
@Jason Campbell raise an interesting point : is it better or worse to use a hinting tool ttfautohint (based on FreeType), to hint for fonts targeting another rendering engine (Microsoft's), or using MS VTT to build libre fonts targeting platforms where Freetype is used for rendering; or should one always use the same tool set for the platform concerned. i.e. MS VTT for fonts used on MS platforms, ttfautohint for non-MS ones.
That was the question he was asking: can one use a hint-checking tool built around one engine to check hinting errors from tools targeting another. One might argue it is better: no secret knowledge working around each others' bugs.