How to exclude forms from processing by Hide Submit module?
The 2.x branch introduced hook_hide_submit_alter() which can be implemented to exclude certain forms based on the current path:

function MYMODULE_hide_submit_alter($hide_submit_settings) {

  // IMPORTANT NOTE: given the way module_invoke_all and array_merge work you
  // should not modify and return the original array. Instead create a new one
  // and add only the keys you care about. If two modules implement this hook
  // and try to modify the same values then the default will be used instead.
  $altered_settings = array();  

  // Disable the module for my special form page.
  if (arg(0) == 'my-special-form') {
    $altered_settings['hide_submit']['hide_submit_status'] = FALSE;
  }

  return $altered_settings;
}


There doesn't look to be a way to turn the functionality off for a specific form, just by path. Might be worth a feature request on the module issue queue if that's something you'd like to see.