It wasn't a rollback in much the same way that UPDATEing a row in an MVCC database doesn't actually overwrite that row, it just creates a new version of it that

It wasn't a rollback in much the same way that UPDATEing a row in an MVCC database doesn't actually overwrite that row, it just creates a new version of it that becomes the version that people tend to care about from that point on.