My first history tutorial in university impressed on one key way to see history – Doubt. That should be one of the first things on your mind when you see the ‘evidence’, according to my professor. Check your source! How important should this concept be.
This is illustrated most definitively in medical care. When presented with a diagnosis or treatment approach, it would be wise to seek a second opinion. Such confirmation would enable you to make an informed decision and perhaps in some cases save your life.
I could go citing more examples in investigation or even researching for overseas trips (from my own experience), but the premise is very simple. As far as possible, do cross reference the information you have against other reliable and relevant sources of advice/evidence before making choices.