Aside from Bitcoin news/events, you need to know that Bitcoin is paired with other countries' currencies, so there is no how the news pertaining to those countries will not affect their currency, and in turn affect the price of Bitcoin.

It now depends on:

1. The news effect (good or bad), and
2. The News impact (Low, Medium and High).

These factors have always proved that it is not necessary for bad news to paint a completely negative pattern on the market chart, because the effect may not be much, and Bitcoin might even be stronger or weaker at the time f the news/event. But surely, at times, it happens as you stated.