He remembers what people were wearing?
Sounds like BS
You would be surprised at what some people can remember.
There are certain things that I remember very well, and see them almost as clearly as the moment that it occurred.
Some are very significant events in my life. But, there are others that stick in my mind for no discernible reason.
But, I can't remember where I left my car keys.
The article says that Trump gave this witness his cufflinks. That may be the trigger that made the trigger that made this event memorable.