The shares are paid for. Burton took a loan to buy the shares....

The shares are paid for. Burton took a loan to buy the shares. The loan was from the company, but don't confuse ownership of the shares with an outstanding debt to the company. The shares are fully paid for and have voting rights the same as any other fully-paid shares. The fact that Burton owes an outstanding debt to the company is not relevant to his right to vote his shares- he was entitled to vote the shares, and will be entitled to vote any that he has left at the AGM.

Burton apparently no longer appears in the Top20 shareholders. That could be an issue. I thought the collateral for the loan was the shares, so I would have thought he couldn't divest himself of the shares before paying out the loan - but I am not a lawyer, and I am not privy to the actual conditions of the loan.

The bottom line is that the shares were bought and paid for - no issue with ownership or voting entitlements. The conditions and granting of the loan might be something that could be looked at, but the shares are paid for and owned by Burton - unless the company has called in the loan and has recovered the shares as collateral.