You say "It's quite possible that Boris may have *looked* at John's original code" but Boris clearly states that he forked John's code.  If you were there you should know this.  

The question of how different they are is a red herring.  The point is that it did not originate at or with Microsoft the way you claim.  No matter how much Boris (or other Microsoft employees) changed it, it did not originate inside Microsoft.  Boris is quite up-front about this, so why can't you be?  I'm in no way putting down his contributions, as I'm sure they are very considerable.  But no matter how sizable his contributions were, your claim is false.   Someone already pointed this out to you and you dismissed them.  Now you say I'm snarky for pointing it out more bluntly.