Yes+No" answer+Status
Closed
Yes+No" answer+*creator
Yes+No" answer+*when created
Wednesday, January 02, 2019 12:31 PM UTC
Yes+No" answer+issue
It is possible to select both YES and NO options as an answer
Yes+No" answer+screenshot
Yes+No" answer+Discussion
That's because it's a multi-category metric. If it's multi-category, you can select more than one answer. (The software doesn't ponder the meanings of "yes" and "no").
If the metric's value type is changed to "Category", this should not be possible.