No one ever knows where the next client will come from. So, it is sound advice in any field, including law firm marketing, to not burn bridges with former partners, associates, staff, and the firm itself. Even if the parting was less than cheerful on either side, time heals all wounds.
Carolyn Elefant at MyShingle has a great post that emphasizes the point. She obtained a client from her former law firm some 14 years after they parted ways under other than happy circumstances. As she relates the story, they had little or no dealings for at least a year after she was let go. She re-established contact because she needed help with a case. From there, a cordial relationship returned with professional dealings back and forth over the past dozen years. Then, her former firm had a conflict involving a client (with whom Carolyn had worked when she was there), and a partner referred the client to her. The client actually requested her, but that isn’t the point of the story. Assuredly, if bridges had been burned, the partner could have found a way to ensure it didn’t happen.
When I was CMO at a large firm, I remember the skepticism of a number of partners when we instituted an alumni program, and invited former firm lawyers to a party. Not all those departures were on friendly terms (no matter on which side) either. Several of the current partners were truly surprised when certain former attorneys showed up. The event was a total success. So much so, that another party was quickly planned in another city.
Since a significant number of referrals, even today, come from other lawyers, why would anyone in their right mind want to burn bridges, including with those on the other side of a matter, when they could be a source of new business?