"I changed my mind earlier than that ... firstly remember between March and the actual general election ... a financial earthquake occurred in on our European doorstep."
Besides, Clegg's claim shouldn't be all that surprising. As I wrote before the election, all signs were that he, and people like David Laws, were just as hawkish on the public finances as the Tories, if not more so – and that the limper approach to deficit reduction came at Vince Cable's insistence. If anything, Clegg's "change of mind" may well have come as his profile started to eclipse Cable's after the TV debates, and it has now been allowed to flourish in partnership with the Tories. This could well be a story about Clegg and Cable's relative influence within the Lib Dems, as much as anything else.
This isn't to say that Clegg doesn't have questions to answer, particularly to his own party. The fact that Clegg was railing against 'Tory cuts' in May leaves a sour taste – was he, on some level, being dishonest then, or being dishonest now? But I'd prefer to characterise this apparent "U-turn" another way: once a hawk, always a hawk.