I have a high vision/high agility back and I've almost never seen this UNLESS there are defenders right on me and I'm trying to juke them.
Honestly, I think low vision causes this, as you are uncertain of where to go. Maybe lower agility too. It's probably speed backs who think they're elusive. They're the cause of many, many elusive complaints.
Now, I know it happens occasionally regardless, but I've very, very rarely seen it. And Bort has been tweaking it for a long time, and he's happier with where it is now.