Their error, as stated in the linked abstract, is less than 0.3%. So, if you believe they're doing statistics correctly, yes, the signal is greater than the noise. More importantly, even, say 1.0 - 0.3 = 0.7% is HUGE: the common estimate of matter-antimatter asymmetry at the big bang was merely a billion-and-one to a billion. (linky: http://livefromcern.web.cern.ch/livefromcern/antimatter/academy/AM-travel02c.html). And that extra one in a billion is all the matter we have today.