Full Idea
If Tek is borderline tall, the unclarity does not seem to be epistemic, because no amount of further information about his exact height (or the heights of others) could help us decide whether he is tall.
Gist of Idea
If someone is borderline tall, no further information is likely to resolve the question
Source
R Keefe / P Smith (Intro: Theories of Vagueness [1997], §1)
Book Reference
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.2
A Reaction
One should add also that information about social conventions or conventions about the usage of the word 'tall' will not help either. It seems fairly obvious that God would not know whether Tek is tall, so the epistemic view is certainly counterintuitive.