It is also criminal in some jurisdictions I believe. However, it is fine as long as you inform the party you are recording. I do it all the time for compliance reasons and it is standard in the financial industry, among others.
If you are going to report on the conversation after the fact, especially in a public and in print as you did, it is always wise to have a recording or at least a transcript. This is standard for reporters. In the absence of this, your testimony is unreliable, hearsay.