Does an attorney have to do anything which will injure his former client in any matter in which he formally represented him?

There are exceptions to the general rule that an attorney may not do anything which will injure his former client in any matter in which he formally represented him and may not at any time use against his former client knowledge or information acquired by virtue of the previous relationship. An exception may exist, where the new employment is not inconsistent with the former employment or where the client expressly or impliedly consents to the adverse representation. (Ward v. Superior Court (1977) 70 Cal.App.3d 23, 31, 138 Cal.Rptr. 532.)