OBVIOUSLY, there was a back up as the records were eventually found. You are going off the basis that the therapist is evil, not that they made an honest mistake. You are trying to make a case that there is something willfully fishy going on.
That makes you sound paranoid and out to get the therapist.
I've had providers willfully with hold records they did have access to immediately. I've had providers engage in CRIMINAL acts against me. And the state/feds don't even care about that.
I filed a complaint against a seriously abusive provider. I had a nurse (not associated with the abuser) who was with me at the time. I listed the nurse as the WITNESS, but the licensing board investigated the nurse (who was not my provider, just a friend/witness) for misconduct.
I once went into a doctor's office with handcuffs prepared to lock myself to something in the office until they turned over the records.
If you were rational about it, you would be more credible.
Something like 'the therapist neglected to back up files. due to that oversight, she was not able to retrieve my records due to a computer virus.
It sounds like the therapist was just being lazy, not abusive like you make her out to be.