Page 261 and 262 are very dense where Sedley is asking why the Epicureans seemed to concede a part of the argument.
We'll ask Don to comment particularly on that one!
What's going through my mind too is that these are the 70 BC Roman Epicureans like Torquatus who were willing to deviate from Epicurus, so I wouldn't concede that any concessions made by them were necessarily made by Epicurus himself.