This might be a sort of marker about the limits of un-disturbedness.
I think this is correct Eikadistes. What I think we can see in the discussion in Tusculan Disputations is that the Stoics were asserting that the good/wise/happy man is going to have no part of evil, and therefore we cannot ever label pain as evil. Epicurus is willing to call pain evil, but he knows that the happy man will still have times when he experiences pain, so he stresses that we can still be happy even when we are in pain, as in his last days.
Epicurus' view of happiness is therefore much more logical and consistent with human experience than that of the Stoics.