Hello, thank you for the question. I can clarify this for you, but you're not going to like my answer. Don't shoot the messenger please.
Firstly, you're correct that many court houses have security cameras in parts of the building. I've been in plenty where there were no cameras in the halls and courtrooms, and I've been in courthouses where there were cameras everywhere. There are usually cameras in the "lock up" to protect the prisoners and the staff/guards from allegations of abuse by each other, or to record what happens if there's a fight or a search, but that's not what you're asking about.
It's against the law for the public to video tape or take pictures in court. If there is a surveillance system, it's for security purposes rather than to record what's said to be used in the proceedings. So your lawyer is right on that count; only what's "on the record" gets recorded by the court reporter and stenographer. There are plenty of "off the record" discussions that go on in a court, such as when the court calls counsel to the bench for a quick talk, or calls counsel to the judge's chambers to discuss how the case is being handled, or when the judge says to go "off the record", or when there's a settlement conference including negotiations as to result, which won't go "on the record". Anything that's on the record can be acquired by ordering the transcript, which is typical for appeals.
If you want a recording of the conversations between the police/crown/lawyers made before court was in session, or out in the hallway, or even in the courtroom before the court has been called to order, you won't get them from ordering a transcript because such recordings are only made when court is in session.
If you want to get security footage, that's a whole other kettle of fish. You could make application for that, but not because you want to use it for this current case as evidence. It's not "on the record" and thus the court won't put any weight on it. If you can allege fraud or criminal collusion between those parties then you have a shot at getting it, but again such recordings if they exist are completely different from what the court reporter and stenographer record.
So you're right, there may well be a security recording. But it's different from the record of the case. So ordering the record won't show what you want.
Does that make sense?