In most states in the US, there is a legal requirement to both keep secured records and to destroy such records after a determined date post treatment. I really don't think most Ts consider those records as evidence to use against clients. Most I have known prefer to put only the barest minimum of info into progress notes in order to protect client confidentiality. At the same time, they do need to protect themselves legally by noting any comments which might indicate a potential danger to a client or others, and by noting any response or intervention they have performed. Their notes in many cases can serve as evidence of their rationale for not recommending the hospitalization of a client. So the notes can protect you.

I think in my state, the regulation was that notes be kept for 10 years after treatment ends, or the retirement of the T. At that point, they must be destroyed and proof provided. My T retired, and we talked about records; he had an arrangement with a professional shredding company to destroy records at the appropriate time, and had arranged for secured custody of the records until that time.