Ah I should have been more specific. He said ~"youre wrong", then some hours later, after Musk had prompted him for a real argument, he made an attempt at a constructive response. By "up front", I mean on tweet 1.
His argument wasn't even that great (because there is no good argument, and that's why one wouldn't take the bait if they actually like their job), and by then I'm afraid the axe had already been sharpened.
I didn't have the direct link and found them by browsing.
The facts are in replies, not standalone Tweets, so you have to know which Tweet to start with. From his profile, click on "I have spent ~6yrs working on Twitter for Android and can say this is wrong."
His argument wasn't even that great (because there is no good argument, and that's why one wouldn't take the bait if they actually like their job), and by then I'm afraid the axe had already been sharpened.