(a) Any matter admitted in response to a request for admission is conclusively established against the party making the admission in the pending action, unless the court has permitted withdrawal or amendment of that admission under Section 2033.300. (b) Notwithstanding subdivision (a), any admission made by a party under this section is binding only on that party and is made for the purpose of the pending action only. It is not an admission by that party for any other purpose, and it shall not be