If their statement is that they haven't changed the weights, there still an immense number of things they can toy with. For example, the prompt may add more 's

If their statement is that they haven't changed the weights, there still an immense number of things they can toy with. For example, the prompt may add more 'safety' language in it, which can cause strange differences to occur, or typical_p sampling values, top_p, top_k, etc, or if they do use mixture of experts, they may even be able to 'use less experts' and only run 1/4 of the models, such that the speed is improved greatly. There's plenty of ways to make the model change output without retraining.