Final answer:
The term for mistakenly flagged non-concerning events is 'false positives', commonly used in IT security and various other fields.
Step-by-step explanation:
The term used for events that mistakenly were flagged and aren't truly events to be concerned with is false positives. This term is commonly used in the context of computer security and information technology. False positives occur when a system incorrectly identifies a harmless action as malicious, such as a security program flagging a safe file as a virus. This can lead to unnecessary actions or concern.
In a broader sense, false positives can happen in various fields, such as medical testing where a test incorrectly indicates the presence of a condition when it is not actually present, or in statistical data analysis where an inference is incorrectly drawn due to an anomaly.