canada
I know you have asked about whether A can "personally sue M." I present another alternative: a complaint to a human rights commission or tribunal.
In Canada and its provinces there are human rights commissions/tribunals established to vindicate the rights granted under Canada's Human Rights Act and similar provincial human rights statutes. M's actions appear to be prohibited discrimination under all of these statutes, even though A ultimately did not lose her job. M's actions are not merely an attempt at prohibited discrimination; they are prohibted discrimination. Whether M's actions and a connection to a "prohibited ground of discrimination" can be proven is a separate issue.
For example, under the Canadian Human Rights Act, it is a "discriminatory practice" to "harass an individual on a prohibited ground of discrimination" "in matters related to employment." Under the Ontario Human Rights Code, "Every person who is an employee has a right to freedom from harassment in the workplace... because of ... disability."
The Canadian Human Rights Tribunal says (and I've highlighted a couple of the remedies that seem particuarly relevant to your hypothetical):
If the Tribunal finds that a complaint of discrimination is eatablished, it can make an order against the person who engaged in the discriminatory practice. This order can include the following terms:
- cease the discriminatory practice and take measures to prevent the practice from occurring in the future (see s. 53(2)(a) of the Act);
- make available to the victim the rights, opportunities or privileges that were denied (see s. 53(2)(b) of the Act);
- compensate the victim for any lost wages as a result of the discrimination (see s. 53(2)(c) of the Act);
- compensate the victim for the additional costs of obtaining alternative goods, services, facilities or accommodation as a result of the discrimination (see s. 53(2)(d) of the Act);
- compensate the victim up to $20,000 for any pain and suffering that the victim experienced as a result of the discrimination (see s. 53(2)(e) of the Act);
- compensate the victim up to $20,000 if the discrimination was wilful or reckless (see s. 53(3) of the Act); and,
- award interest on an order to pay financial compensation (see s. 53(4) of the Act).
Similar remedies are available in British Columbia.