The term used to describe inappropriate induction of WD symptoms after brief usage with a past addiction is "withdrawal kindling", and it's a fucking bitch, no two ways about it.
However, 30mg OC is a comparably minor addiction so any symptoms will be (subjectively...) minor. An Oxy or two is unlikely to throw you to the wolves again but that will change quickly if you keep it up.
How long were you off Suboxone before the 45mg Oxy and at what dose?