Years ago, I had "deposition training". It lasted about an hour and a half. I found it quite interesting, and it taught me how a clever lawyer would tie me up in knots. I was given a script, a history if you will, about the topic, made up, but I had to respond as if it were true. I was never deposed for real, fortunately, but it was useful being somewhat prepared.
The few Congressional hearings I've heard have obvious questions not anywhere near as tough as what I faced. It's grandstanding, you know what they are going to ask. Maybe a politician could benefit from an hour of "prep" like what I had. Run through it so you feel prepared and understand what is going to be asked and how/whether to respond.
Being prepped is not going to cost half a million obviously. The governor's office should respond to the charge more clearly (but won't).