The trustee if misusing the power or the situation for some wrongful gains then he can be held liable for contradicting the laws or flouting the regulations or clauses made in the bylaws of the trust.
In that situation, if it has been brought to the notice of the president or the secretary of the trust, they can initiate action as per the provisions of the bylaws seeking explanation and holding him guilty of the offence, if he has committed one by revealing the details of the meetings to a member of the body.
In any case the trustee cannot be held liable for committing any offence if the said details were passed on to one of the members only.
There is no such rule that a member has to give a request in writing to know about the details of meeting or the minutes of the meeting which was concluded.
The member has full rights to know about them and he can demand from the secretary to show the minutes book to know whether the minutes were recorded as per the meeting that concluded.