This poll is an average of results over a one week period of time. The post-debate portion of this is only one of those seven days, whereas there are two days that are after the release of the video tape. This poll will not significantly reflect the events of Friday and Sunday until at least Thursday morning. Don’t be too concerned.
Exactly. It's a rolling average.
I wouldn't be too concerned until 7 days (evenings) post-debate. That would be NEXT Tuesday. Volatility should be expected, considering the events. (Of course that's if nothing new happens -- involving Clinton, Trump or the rest of The Universe. The chances of that are probably about 0.)