If a candidate is understandable and has the underlying officer qualities (and that's a debate for later) then the candidate is likely to get through OASC. If the "rough" language causes problems at IOT then it may possibly impinge on leadership exercises. Too many "Ds" and you're on your way!
I graduated plenty of Scottish officers and consumed vast quantities of scotch in the process
As a further aside.......In my present position (Mayor of a Shire about the size of Surrey or South Yorkshire) I am in the process of shortlisting candidates for the CEO job (approx Aus$140,000 pa). Of the 30 applicants my Council has binned 10 because of simple English errors on their applications and CVs, and forgetting to submit information asked for. Close enough might be good enough for them but it HAS made a difference, in this case, in their employability.
As I said earlier Harri, "You feeling lucky?"