It's good that the therapy ended after a few sessions. Zagup's description of a 2 year therapeutic relationship before switching to intense friendship is more concerning. I would be concerned if either of these therapists were still practicing as the weren't able to hold effective therapeutic boundaries with you.
One of the CRUCIAL things about the therapeutic relationship is the therapists ability to hold the boundary..... becoming close friends with one's therapist is similar to becoming lovers. It indicates the therapist is using the client to get their own needs met and not prioritising the clients process in developing support structures outside the therapy room. I suspect you are female and your ex-therapists are both female. If you swapped the therapists gender to male...... would this make a difference to how you felt about the relationship, and how others (eg partners) might interpret the relationship?
Any ethical therapist will have a supervisor. If the relationship shifts, it's the therapists ethical responsibility to talk to their supervisor about what they are feeling and untangle the therapeutic process, therapists needs and the clients needs. In the therapeutic relationship the therapist is in service of the client and the supervisor is there to make sure this happens. A therapist who doesn't have a supervisor or doesn't talk openly to them and take the supervisors advice is acting unethically...... and a danger to their clients.
I would wonder whether..... if you realise that your ex-therapist friend was acting unethically with you, and is still practicing (maybe without supervision)..... would you ... as their friend, be able to talk about this and advise them to go and see a supervisor?? If not, I'd suggest the friendship isn't as deep as you might think it is.....