To my knowledge the reviewer is a native English speaker, but I don't know that for certain.
The reviewer had also used the term "on regards to" whereas I had used the term "in regards to". When I Googled the terms I found I was using nonstandard English (not sure about his term though), so I've learnt something new.
Another term he had used was "Language is still improved", which I took to mean "their English needs improving".
Since I'm not university trained, I don't know what the current state of English is within that environment, which is the reason I asked the question.