A board of directors solicits internal employee questions

And many of the questions are aimed at a particular manager. The question was why does this person trash our branch on Facebook?
Why is this person being paid $x amount to only do this and that?
Why does this person not communicate what we sent to be communicated?

The initial platform for the submission of questions would be an anonymous one, but due to circumstances all ee's were asked to send in their questions via email to a particular board member. An employee within took it upon himself to collect all the questions and submit to the board anonymously, which a board member thanked him for doing so.

The complaining manager was accidentally sent the questions before finding out they had been printed and said nothing. Only after being told by another staff member that they were on the printer he now has complained defamation and a hostile work environment.
HR's conclusion after investigating was that the work environment is not hostile, but the complainant wants to know who printed the questions for a potential libel claim? Is HR required to disclose the person who printed the questions? Regardless, does this actually amount to a case of libel because the questions were printed?