He probably doesn't. But he's a pompous A__ that assumes too much about what people post. He apparently thought you suggested putting your current meter in parallel with the external shunt that he proposed. So he just couldn't wait to jump on that and show it would be inaccurate by up to 47.6% of scale (which, of course it would be very inaccurate).
He didn't stop to think that maybe, just maybe, you would hook the DMM current meter up correctly and get a respectably accurate reading *without* following his advice/method.
daestrom