Hi,
It all depends on the glass and the depth of the scratch.
You can buff it out with cerium oxide but only if A) The glass is not toughened i.e a patio door or similar and B) the scratch is not deep enough to catch your nail on.
Be prepared to be there for many hours if you intend sorting it. If you have already admitted liability it might be easier / more cost effective to simply offer compensation.
Good luck