To move or not to move aside..
I really don't see what good can a case like this serve to shareholder..
whether the shareholder win or lose or forces hsbc to give this particular dividend or not to give, on the overall it will not be a good deal.. they will be footing the legal fees for both sides of the case, and if the bank loses the case changes are the reputation impact will force the share price down further.
Now without giving the dividend the money sits inside the bank and the NAV of every share remains higher than giving out the dividends.
Maybe what they can try is to force the bank to cut 3% of cost (e.g. dont pay the executive and the staff half a year salary, etc)... but certainly a case on paying of that dividend will not be that economically meaningful.