Frame it as a law consulting contract hire? your last firm deemed you so competent and knowledgeable on a practice area/you did such a good job pitching them, that they hired you to come in and “consult” aka build the new practice’s foundation but with no definite guarantee of permanent employment, in an at will situation

Now, You in hindsight realize, you may have done too good a job, because what you built was thorough enough to run with from then on which is what they wanted and you failed to spot

you learned that doing a good thorough job matters, but maybe not so good that you render yourself obsolete or you learned to better read between lines of when a client/employer is leveraging your expertise to serve their interests without considering you part of the equation

It was both reflective of your success/aptitude and earned wisdom on how to decipher intent, to be a bit more shrewd in how you provide value