Both the use of “veteran” and “tenure” that you provide as incorrect are recognized as correct by OED and are common colloquial uses.

The term is used colloquially so often that I didn't even associate it with military service in this context in the least.

> A veteran (from Latin vetus 'old') is a person who has significant experience (and is usually adept and esteemed) and expertise in a particular occupation or field.[1] A military veteran is a person who is no longer in a military.[2]

https://en.wikipedia.org/wiki/Veteran

That's one definition. A word can have more than one definition.

Cambridge: "a person who has had a lot of experience of a particular activity"[1]

Merriam-Webster: "a person of long experience usually in some occupation or skill (such as politics or the arts)[2]

Oxford: "A person with long experience in a particular (non-military) position, field, or activity; any experienced or ageing person."[3]

Vocabulary.com: "Veteran commonly refers to someone who has fought in a war––think Veterans' Day, the Vietnam Veterans' Memorial––but, in fact, the word can mean anyone with experience in a particular field."[4]

I could go on. They used it correctly. 10 years is plenty of experience for this field to use the term veteran.

[1]: https://dictionary.cambridge.org/us/dictionary/english/veter...

[2]: https://www.merriam-webster.com/dictionary/veteran

[3]: https://www.oed.com/search/dictionary/?scope=Entries&q=veter...

[4]: https://www.vocabulary.com/dictionary/veteran

Veteran has a broader meaning than just ex-military. Saying you're "a veteran" implies military service, while "a veteran of $foo" does not.

You just aren't familiar with the more generic definitions of "veteran" and "tenure". "Tenure", especially, is not reserved for the well-defined academic track.