Off the hook (6)
(Other definitions for lit that I've seen before include "Illuminated" , "Creative writing, in short" , "landed here" , "was illuminating" , "Set alight" .)
'off the hook' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for exempt that I've seen before include "Release" , "not expected to pay" , "Free from liability. excused" , "Not subject to a law" , "Not subject to, taxation perhaps" .)