Aaf: lazy=>true and using .highlight causes DB request?!?

i want to perform searches that don’t hit the database and then
hightlight 1 or 2 fields from the store.

when i do
Document.find_with_ferret(query, {:lazy=>true})

and then access
the content gets pulled from the index without any DB request.

but when i do
hit.highlight(query, {field => :description})

i see a request made to the DB
Document Load (0.4ms) SELECT * FROM documents WHERE
(documents.id = 5)

what can i do to prevent this DB hit ?