[bmitc]

As far as I can tell, they are only available if you have the direct link. They don’t show up in the thread or on his profile.

[bananapub]

is there any reasonable explanation for why that is the case?

[leereeves]

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."