It is not good to manipulate with DOM (including checking of attributes) in any place except directives. You can add into scope some value indicating if link should be disabled.
But other problem is that ngDisabled does not work on anything except form controls, so you can’t use it with <a>, but you can use it with <button> and style it as link.
Another way is to use lazy evaluation of expressions like isDisabled || action() so action wouold not be called if isDisabled is true.
Here goes both solutions: http://plnkr.co/edit/5d5R5KfD4PCE8vS3OSSx?p=preview