Do not pay a lot of attention to single polls. Poll aggregators (even with flaws like RealClearPolitics) are so much better, and a predictive model (Nate Silver or the new 538) is even better. Great pollsters don't herd and are not afraid of publishing outliers.
If we see the overall aggregate start to tend more toward Harris, that's significant and this poll was an early sign. If it doesn't, then this poll was just an outlier.
Oh wow, deep cut! I had that buried somewhere in the back of my brain.