It is not standard at all to include R&D in gross margins for most companies. Also this is a pretty widely known fact that happened from the beginning.
And dealer ship costs can be called distribution costs, also not that non standard to not include that in gross margins. Just because some auto companies do does not mean this is standard.
COGS should generally include what it cost to build it, and OPEX should include distribution costs, corporate R&D etc.
And this has been pretty well known. So horse**** like this:
'[...]the Board awarded Musk stock options based on achieving a certain gross margin threshold, without ever defining how to calculate gross margin[...]'
Is not really that controversial. It is not like R&D was part of COGS at first and Musk pulled a bait and switch. This has been pretty consistent. This guy is obviously pretty biased.
Honestly anybody speaking in platitudes right now about Musk and Tesla (whether they think he is some demigod, or a complete fraud) are overconfident morons.