I don't think any new or surprise questions pop up in oral argument. Everything has been mapped out in the briefing documents, and hashed out sever times in lower courts.
In fact, I think it would be a bad thing if the court swung on oral arguments. These are very complex topics prepared by an army of lawyers on each side. They should not hinge on if a single presenter doesn't have a clear an concise answer within two seconds of being asked it.
I don't doubt everyone prepares. However, there are arguments if you listen to where the attorneys don't have a prepared answer / don't have good answers and the judges genuinely sound surprised.
As for the rulings there's A LOT more than ruling one way or another, the ruling itself can range in all sorts of directions.
In fact, I think it would be a bad thing if the court swung on oral arguments. These are very complex topics prepared by an army of lawyers on each side. They should not hinge on if a single presenter doesn't have a clear an concise answer within two seconds of being asked it.