My take: The comments occured on a rope-line, not in a press conference venue. As such, the blogger should have disclosed to Clinton that he was, in fact, "on the record."
Of course, Clinton should assume everything he says is "on the record." My guess is that he frankly doesn't care that this became public...
Does Anybody Understand What These Never Trump Republicans Think They’re Achieving?
FISA Reform Could Be A Much Needed GOP Victory
Trump and the Forever War in Afghanistan