Bonilla got 48.6% in the 11/8 election, and 6 Democrats together got 48.7% -- it makes no sense for Bonilla to get a much lower percentage now, so this must be a unrepresentative bunch of precincts, which often happens in the early returns.
A special election is all about base turnout. You can throw out the regular election results. Bonilla had 57K in November, but likely won't get close to that today. I wouldn't be surprised if this holds. I hope it doesn't, but the data I heard about before today wasn't encouraging.
You, unfortunately, aren't accounting for the "risen dead" vote. /s
I agree, however, that it doesn't sound quite right. :-/