Core Retail came out exactly as expected, and Headline deviated by 0.3. It was expected at -0.2, and came out at -0.5. So, a negative number was already priced in, and since Core didn't deviate at all, the small deviation on Headline wasn't enough to move the market that much initially. So this was a no trade really.
Hope that helps.
Also, it's important to keep in mind that reactions to news don't always make sense. Two years ago news made so little sense that it was actually profitable to trade against the number (i.e. if it was a positive UK report you'd sell the pound.) We did that a lot in Felix's old Diamonds trading room. A lot of times this happens because banks use news to sweep stops both long and short. One look at an NFP chart almost any month shows you that.
If you're interested, "Beat the Forex Dealer" is a book written by a former MIG employee that describes a lot of this stuff.