It is perfectly fine. If the thread had started to be a few months old, maybe. There is no hard rule, just common sense AFAIK. Additional leeway would probably be given in this instance as this thread is very specific to your project, as opposed to another member bumping this to ask a follow up question.
I know this reply comes late, I do hope that it is still a valid to post in topic.
Great! When you're happy with it, you can post it here again for further feedback.
I am currently changing the code to match the suggestions made here.
I don't believe there is any sensible meaning to the return value of OnPaddleCollision, thus I would use the "void" version. I'd recommend against including return types when the result is irrelevant to the caller.
would a method named 'OnPaddleCollision' be of type Bool or type Void
would I: check for a collision with the paddle/ball in the arena and, if one occurs, call the void Ball::OnPaddleCollision()