Given the impact this attitude had on you, it would be beneficial for you to speak directly with the Manager and clarify your position. Explain your intention was not to violate a policy/regulation and you did not deliberately cross some boundary. Some people in Management may have an issue with volunteers but equally, many are truly grateful for the work they do.
There is no normal/abnormal here, simply different perspectives about a situation. Focus on your volunteer work and if a similar situation arises in the future, speak to a Manager for clarification. Remember, the more you know the more you can do.
Certainly it is normal. She saw you breaking the rules on phone use and came to deal with it. You explained that you had been told by so and so that that was just fine, and she probably (and rightly) didn't want to badmouth that person in your hearing - they probably got an earful from her later.
As other posters have said, you don't know what issues there may have been in the past about phone use, but it's my guess that there have been some. She sounds like a woman who is as nervous as h*ll that if someone under her supervision fouls up she will be the one in the firing line.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.