In AFR today, on one hand they are a shareholder on the other a...

In AFR today, on one hand they are a shareholder on the other a buyer who wants 30% of company, there must be a conflict issue here they should be made to abstain in the vote, how is this in the best interest of shareholders?
AFR
"AustralianSuper's confirmation that it will reject, vote against or not accept any takeover proposal for Healthscope other than its own shows it is serious about wanting to buy 30 per cent of the company at the lowest possible price."