rank and file vs. managerial

hi,
i would like to ask, an employee (rank and file) expresses his intention to file a complaint against a managerial employee regarding the latter's attitude towards his subordinates. He was advised to make a formal written complain with signature of all employees who support the complaint and forward it to the Administration Department. According to the employee if Administration Department fail to address the complain they will bring the complain to DOLE.
Questions:
1. Was the employee properly advised about the making of report/complain?
2. Can the employee be given sanction for gathering the signatures of other employees who support the complain?
3. What could happen if the complaint was forwarded to DOLE? Will the company be held liable?
4. What can you advise to the company for its proper actions?

Thank you very much and looking forward to your response.

1. Yes. But if you have a union, it's much better if you course it through the union
2. It depends how you drafted your letter and what evidence did you support, and if the manager filed a counter-complaint
3. Most likely, you be have a SENA hearing. It depends what will be the outcome
4. If I were the company's HR, I would set a mediation meeting between the employee and the manager.