As far is my understanding, there were two periods of Libor fixing at Barclay and elsewhere; one prior to 2008 which involved manipulating Libor to boost trading profits indirectly and a second after 2008 where they manipulated Libor to prevent themselves going under.

First of all, disclaimer for Barclays, "they" were all at it, Barclays were just the most thorough in their investigations and the quickest in settling with various regulators. Bob Diamond's ire is somewhat justified for that.

What Bob Diamond is not justified in doing is conflating the two sorts of Libor fixes in which banks were involved.