Answer:
Over-reporting
Step-by-step explanation:
Error of over-reporting occurs when a person reports something as being higher or greater than it really is. It is when an event is described in a disproportionately greater frequency than it actually occurred.
The person who lost his keys and claimed that they were stolen has given a misreport of what happened by disproportionately escalating the event/circumstance surrounding the loss of his keys.