It’s a common dictionary, which is probably not very good in this context. I think it would be more appropriate to refer to ISTQB, as it is likely the most relevant source when it comes to software testing and failures:
Human beings make errors (mistakes), which produce defects (faults, bugs), which in turn may result in failures. Humans make errors for various reasons, such as time pressure, complexity of work products, processes, infrastructure or interactions, or simply because they are tired or lack adequate training
Of course they are an error, what are you talking about.
Error: A mistake; an accidental wrong action or a false statement not made deliberately
It’s a common dictionary, which is probably not very good in this context. I think it would be more appropriate to refer to ISTQB, as it is likely the most relevant source when it comes to software testing and failures:
Or to put it simple:
We’re seeing a failure here.