If you have the motivation and qualities they are looking for, you will pass, regardless of age or background.
This sentence implies OASC was (is?) a pass/fail course. I was there in 88 and it was an attendence course in all but name. To fail (as in chopped without recourse) you had to:
a. Commit a crime
b. Be so hopeless you could not get out of bed in the morning.
c. Voluntarily quit.
d. Get injured.
Only about 7 out of 150 of my entry managed to distinguish themselves as above, most quitting or getting medically discharged.
20 or so were recoursed, but all passed later. As far as I am aware this was par for the course and I do recall being told by a Sqn Cdr that chopping people was becoming relatively unheard of, whatever their shortcomings.